We didn’t live together. We kept in touch _______ writing often.

A. with    B. of  C. on     D. by

He ran off____ I could stop him.

A. before             B. after          C. since          D. when

They had camped once before, ____ they knew what to take.

A. because         B. now          C. so              D. since

Go ____ the gate and you' 11 find the entrance ____ the park ____ the other side.

A. through; to; on B. along ;of; on  C. down; to; at     D. up; of; by

He is running ____ the wind towards the east of the station ____ Tom is running ____ the right.

A. down; and; on B. against; while; on C.for;with;in     D. with; while; to

He wrote the article ____ three days.  

A.at                       B.in                           C.on             D.by

Mary dropped in ____ Mr Smith, but he  wasn' t at home, so she went to drop in ____ Mr Smith's office.          

A. on, on         B. at, at          C. on. at          D. at. on

  11. —Would you like to come to dinner tonight？

    —I’d like to, ___ I’m too busy.

    A. and . B. so

    C. as. D. but

I'd like to go swimming ____ the water is not too cold.

A. for               B. unless             C. if                D. whether

____ you work, you must always serve the people heart and soul.

A. Wherever                  B. Whenever            C. Where                D. When