The new iphone 5 costs so________that I don’t think a student can________ it.

You made many mistakes in your English exams. What will you ___them?

Your mother was angry ______ what you said. [ ]

There is somebody knocking at the door. Who________ it be?—I’m not sure. It ________ be a postman.

Most scientists seem to agree that ________ certain limit should be set on ______sale of cars to ease air pollution.