Trong mặt phẳng tọa độ xOy có ba điện tích điểm (Hình vẽ). Điện tích q1 = + 4μC được giữ tại gốc tọa độ O. Điện tích q₂ = -3μC đặt cố định tại M trên trục Ox, = +5 cm. Điện tích q₃ = -6μC đặt cố định tại N trên trục Oy, =+10 cm. Bỏ lực giữ để điện tích q₁ chuyển động. Sau khi được giải phóng thì điện tích q₁ có gia tốc bằng (Cho biết hạt mang điện tích q₁ có khối lượng m = 5g)

Read the following passage and mark the letter A, B, C, or D to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

                                                         The threat to the Environment

Nowadays people are more aware that wildlife all over the world is in danger. Many species of animals will become (31)_____ if we do not make an effort to protect them. There are many reasons for this. In some cases, animals are (32) _____for their fur or for other valuable parts of their bodies. Some birds, such as parrots, are caught alive and sold as pets. For many animals and birds the problem is that their habitat - the place where they live - is (33) _____ . More land is used for farms, for houses or industry, and there are fewer open spaces than there once were. Farmers use powerful chemicals to help them grow better crops, but these chemicals pollute the environment and (34) _____ wildlife. The most successful animals on earth - human beings - will soon be the only ones (35) _____ , unless we can solve this problem.  

Question 32:

Read the following passage and mark the letter A, B, C, or D to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

                                                         The threat to the Environment

Nowadays people are more aware that wildlife all over the world is in danger. Many species of animals will become (31)_____ if we do not make an effort to protect them. There are many reasons for this. In some cases, animals are (32) _____for their fur or for other valuable parts of their bodies. Some birds, such as parrots, are caught alive and sold as pets. For many animals and birds the problem is that their habitat - the place where they live - is (33) _____ . More land is used for farms, for houses or industry, and there are fewer open spaces than there once were. Farmers use powerful chemicals to help them grow better crops, but these chemicals pollute the environment and (34) _____ wildlife. The most successful animals on earth - human beings - will soon be the only ones (35) _____ , unless we can solve this problem.  

Question 33:

Read the following passage and mark the letter A, B, C, or D to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

                                                         The threat to the Environment

Nowadays people are more aware that wildlife all over the world is in danger. Many species of animals will become (31)_____ if we do not make an effort to protect them. There are many reasons for this. In some cases, animals are (32) _____for their fur or for other valuable parts of their bodies. Some birds, such as parrots, are caught alive and sold as pets. For many animals and birds the problem is that their habitat - the place where they live - is (33) _____ . More land is used for farms, for houses or industry, and there are fewer open spaces than there once were. Farmers use powerful chemicals to help them grow better crops, but these chemicals pollute the environment and (34) _____ wildlife. The most successful animals on earth - human beings - will soon be the only ones (35) _____ , unless we can solve this problem.  

Question 34:

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks:

Rock carvings suggest that Stone Age people were hunting whales for food as early as 2,200 B.C. Such (31)______ hunting is still practised today in a number of societies including the Inuit people of Greenland and North America. Whaling became big (32)_____________ from the seventeenth century as the demand for whale bone and whale oil rose, and the humpback and sperm whales were hunted in increasing large number. (33)_________ just as stocks of these species began to fall, the explosive harpoon gun was invented. This weapon, together with the development of steam-powered ships, enable the whaler to hunt the fast moving fin and blue whales. In 1905, the whaling (34)____________ moved the water of Antarctica. The introduction of massive factory ships enabled the whales to be processed at sea. As a result, the blue whale had virtually disappeared by the 1950s. In 1946, The International Whaling Commision was established to maintain the declining whale populations. Quotas were set but these were often ignored and the numbers continued to fall. Hunting of many species continued until 1986 when the IWC finally responded to international (35)____________ and a band on commercial whaling was introduced.  

Question 35:

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks:

Rock carvings suggest that Stone Age people were hunting whales for food as early as 2,200 B.C. Such (31)______ hunting is still practised today in a number of societies including the Inuit people of Greenland and North America. Whaling became big (32)_____________ from the seventeenth century as the demand for whale bone and whale oil rose, and the humpback and sperm whales were hunted in increasing large number. (33)_________ just as stocks of these species began to fall, the explosive harpoon gun was invented. This weapon, together with the development of steam-powered ships, enable the whaler to hunt the fast moving fin and blue whales. In 1905, the whaling (34)____________ moved the water of Antarctica. The introduction of massive factory ships enabled the whales to be processed at sea. As a result, the blue whale had virtually disappeared by the 1950s. In 1946, The International Whaling Commision was established to maintain the declining whale populations. Quotas were set but these were often ignored and the numbers continued to fall. Hunting of many species continued until 1986 when the IWC finally responded to international (35)____________ and a band on commercial whaling was introduced.  

Question 32:

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks:

Rock carvings suggest that Stone Age people were hunting whales for food as early as 2,200 B.C. Such (31)______ hunting is still practised today in a number of societies including the Inuit people of Greenland and North America. Whaling became big (32)_____________ from the seventeenth century as the demand for whale bone and whale oil rose, and the humpback and sperm whales were hunted in increasing large number. (33)_________ just as stocks of these species began to fall, the explosive harpoon gun was invented. This weapon, together with the development of steam-powered ships, enable the whaler to hunt the fast moving fin and blue whales. In 1905, the whaling (34)____________ moved the water of Antarctica. The introduction of massive factory ships enabled the whales to be processed at sea. As a result, the blue whale had virtually disappeared by the 1950s. In 1946, The International Whaling Commision was established to maintain the declining whale populations. Quotas were set but these were often ignored and the numbers continued to fall. Hunting of many species continued until 1986 when the IWC finally responded to international (35)____________ and a band on commercial whaling was introduced.  

Question 31:

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks:

Rock carvings suggest that Stone Age people were hunting whales for food as early as 2,200 B.C. Such (31)______ hunting is still practised today in a number of societies including the Inuit people of Greenland and North America. Whaling became big (32)_____________ from the seventeenth century as the demand for whale bone and whale oil rose, and the humpback and sperm whales were hunted in increasing large number. (33)_________ just as stocks of these species began to fall, the explosive harpoon gun was invented. This weapon, together with the development of steam-powered ships, enable the whaler to hunt the fast moving fin and blue whales. In 1905, the whaling (34)____________ moved the water of Antarctica. The introduction of massive factory ships enabled the whales to be processed at sea. As a result, the blue whale had virtually disappeared by the 1950s. In 1946, The International Whaling Commision was established to maintain the declining whale populations. Quotas were set but these were often ignored and the numbers continued to fall. Hunting of many species continued until 1986 when the IWC finally responded to international (35)____________ and a band on commercial whaling was introduced.  

Question 34:

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks:

Rock carvings suggest that Stone Age people were hunting whales for food as early as 2,200 B.C. Such (31)______ hunting is still practised today in a number of societies including the Inuit people of Greenland and North America. Whaling became big (32)_____________ from the seventeenth century as the demand for whale bone and whale oil rose, and the humpback and sperm whales were hunted in increasing large number. (33)_________ just as stocks of these species began to fall, the explosive harpoon gun was invented. This weapon, together with the development of steam-powered ships, enable the whaler to hunt the fast moving fin and blue whales. In 1905, the whaling (34)____________ moved the water of Antarctica. The introduction of massive factory ships enabled the whales to be processed at sea. As a result, the blue whale had virtually disappeared by the 1950s. In 1946, The International Whaling Commision was established to maintain the declining whale populations. Quotas were set but these were often ignored and the numbers continued to fall. Hunting of many species continued until 1986 when the IWC finally responded to international (35)____________ and a band on commercial whaling was introduced.  

Question 33:

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

The United States has many different types of families. While most American families are traditional, (31) __________ a father, a mother and one or more children, 22 percent of all American families in 1998 were headed by one parent, usually a woman. In a few families in the United States, there are no children. These (32) ___________ couples may believe that they would not make good parents; they may want freedom from responsibilities of childbearing; or, perhaps they (33) ___________ physically able to have children. Other families in the United States have one adult who is a stepparent. A stepmother or stepfather is a person who joins a family by marrying a father or a mother. Americans (34) ___________ and accept these different types of families. In the United States people have right to privacy and Americans do not believe in telling other Americans what type of family group they must belong to. They respect each other’s choices regarding family groups. Families are very important (35) ___________ Americans.  

Question 34:

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 31 to 35:

The United States has many different types of families. While most American families are traditional, (31) __________ a father, a mother and one or more children, 22 percent of all American families in 1998 were headed by one parent, usually a woman. In a few families in the United States, there are no children. These (32) ___________ couples may believe that they would not make good parents; they may want freedom from responsibilities of childbearing; or, perhaps they (33) ___________ physically able to have children. Other families in the United States have one adult who is a stepparent. A stepmother or stepfather is a person who joins a family by marrying a father or a mother. Americans (34) ___________ and accept these different types of families. In the United States people have right to privacy and Americans do not believe in telling other Americans what type of family group they must belong to. They respect each other’s choices regarding family groups. Families are very important (35) ___________ Americans.  

Question 33: