It’s really not ___________ you to do such a silly thing.
Miss Liu can sing a lot of English songs and she can sing them ___ .
Only one of the answers _______ right .Either he or I________ right.
---- How do you usually go to school, Mary? ----I usually go to school _______ a bus.
Don’t leave the baby at home _____. It’s very _____.
This is______difficult problem that few students can work it out.