—Tom , where is Lucy ?—She ______ be in the library.But I’m not sure.
—Lily, _____ you _____ your ticket? —Not yet!
We couldn’t wait _______ a good rest after the exam.
Although we’ve learned English for years, we have trouble _____ the foreigners.
-----How many students are there in the classroom?------_______.
Students are supposed ________ hard at school.