(    )1. She reached the top of the hill and stopped _______ on a big rock.

         A. to have rested             B. resting 

         C. to rest                    D. rest

(    )2. Do you know the boy _______ under the big tree?

         A. lay    B. lain    C. laying   D. lying

(    )3. You’d better ______ your bike _____ at once. It is Monday tomorrow, you know.

         A. to have, mend              B. have, mended 

         C. have, to mend              D. to have, mended

(    )4. --- Look! The lights in the classroom are still on.

         --- Oh, I forgot _______.

         A. turning them off          B. turn them off 

         C. to turn them off          D. having turned them off