It is nearly seven o’clock. Jack 　　　 be here at any moment.

— Mum, would you please buy me an MP5 player?— If you can help do some housework the whole vacation，you ____ have one as a reward.

—Whose notebook is this?—It         Jane’s. It has her name on it.

Keep up good state of mind even if you ________ fail plenty of times.

Nobody knows for sure how dinosaurs died out 65,000,000 years ago. It _______ because of sudden changes of their living conditions.