What do you think of teaching, Bob?—I find it fun and challenging. It is a job ______ you are doing something serious but interesting.

till working on my project.— Oh, you’ll miss the deadline. Time is____________.

When you go outing with your sisters, you must see to_____ that they are safe. 　　[ ]

Must I give the dictionary back to the library nowNo,you_______.You can_______ it for another two weeks

You have worked hard all week so you _____ a good rest.[ ]