He finally contracted the disease. He was aware of the importance of preventive measures only then.

A. before the 1920s

B. in the early 1920s

C. in the mid-1920s

D. in the late 1920s

A. Nutritious

B.affect

C. senses

D. smell

A. Joe is not as hard-working as his brother.

B. Joe's brother is not as hard-working as he is.

C. Joe is less hard-working than his brother.

D. Joe's brother is more hard-working than he is.

A.assists me by

B.asks me to help with

C.pleases me by

D.serves me with

A.Different points of view are the main problem between generations in America.

B.Generation gap doesn't cause a big problem in American families.

C.The areas of difference in generation gap have changed over the years.

D.The generation gap in the past was different from that in the modern time.

A. drank

B. shame

C.chase

D. wage

A. although

B. for the fear that

C. provided that

D. unless