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[说明]已知关系R(A，B，C，D) 和函数依赖集F为AB—＞D，C—＞，A，D—＞C。 [问题3]关系R是否满足第二范式第三范式BCNF范式

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Questions 14 to 17 are based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions. Now listen to the passage. Why does the professor mention a five story building

A. To correct a common misunderstanding about grasshoppers.
B. To help explain how well’ grasshoppers can jump.
C. To compare the size of grasshopper with that of other insects.
D. To show how quickly grasshoppers respond to danger.

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What does the man say is a drawback to the process of restoring books

A. It’s very expensive.
B. It hasn’t proven to be totally effective.
C. It can be damaging to some books.
D. It can’t be used on books published before 1850.

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Questions 14 to 17 are based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions. Now listen to the passage. What is the function of the sensory organs that the professor discusses

A. They detect nerve impulses transmitted to a grasshopper’s legs.
B. They sense how far a grasshopper has jumped.
C. They detect changes in air pressure.
D. They help a grasshopper find food.

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Questions 24 and 25 are based on the following news. At the end of the news item, you will be given 10 seconds to answer the questions. Now listen to the news. How many people have died in the disaster

A. Less than 600.
B. Less than 640.
C. 614 or so.
D. More than 640.

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