The Sound of Music is the first English film   I have ever seen.

 —Have you finished your work yet?—No, I’ll finish it in ________ fifteen minutes. 

 — How many students are going to the Great Wall? — ____.

Environment protection requires our joint effort. ______ will be achieved unless we work well together.

_____ could be better than having a cup of tea after a day of work, which helps you relax.