_____ to finish this composition in such a short time is a mystery.

Thefirst thing we should do is toprotect the wild animals .

Guess what？I came first in that contest.—Great！You ________ a lot during the past two weeks.

What is it ________ made her upset— It is the missing bike.

You must help me with the housework first, ________ I can’t go to play tennis with you.