It is difficult for us to explain phenomena that we have little or __________ direct knowledge.

A. arouse

B. rise

C. arise

D, abide

A. diagnosed

B. determined

C. deduced

D. discovered

A. interaction

B. intervals

C. interruptions

D. interpretation

A. But for

B. Because of

C. By means of

D. Due to

A. transforming

B. transferring

C. altering

D. shifting

A. only human beings have problem-solving intelligence

B. a person' s memory is different from a computer' s in every respect

C. animals are able to solve only very simple problems

D. animals solve problems by instincts rather than intelligence

A. "in connection with"

B. "expressed by"

C. "consisting"

D. "by means of"

A. What would life be like without memory ?

B. Memory is of vital importance to life.

C. How is a person' s memory different from an animal' s or a computer' s?

D. What is contained in memory ?

A. To sell a bicycle for $

B. To get some money for old books at a garage sale.

C. To buy things you need or want.

D. To get paid for your work.

A. In the Philippines.

B. In China.

C. In Africa.

D. We don' t know.