As to the greenhouse effect, the author __________

A.caused widespread damage in the countryside

B.affected the entire eastern half of the United States

C.had damaging effect on health

D.existed merely in urban and industries areas

A. jumping

B. five track and field events

C. throwing

D. ten track and field events

A. before he was nine years old

B. when he was 16 years old

C. when he was 24 years old

D. before his parents passed away

A. fishing

B. hunting

C. swimming

D. singing

A. India

B. Pennsylvania

C. Oklahoma

D. Sweden

A.Never mind. Shall we meet on Sunday?

B.Your project? I have no time studying your project.

C.OK. What about Friday morning?

D.OK. Library is the best place for us to meet.

A.Speaking. B.I am Helen. C.It' s me. D.This is me.

A.That' s very regretful. B.That' s pitiful.

C.That' s too bad. D.That' s a pity.

A.You' re kidding ! B.Congratulations !

C.Is it a real thing? D.Good luck!

A.How do you do? B.Nice to meet you.

C.Fancy meeting you here. D.Well. How have you been?