the helicopter landed ... the roof of the building.

a. at  b. in  c. over  d. on

you'd better go to bed early, ...?

a. hadn't you  b. didn't you  c. wouldn't you  d. don't you

a. laughed  b. smiled  c. cried  d. phoned

he didn't want to ... late for the interview.

a. arrive  b. arriving  c. to arrive  d. having arrived