Look out! The train ________

It’s time for classDon’t knock ____ outside the classroom.[ ]

do youthink of the furniture on sale—Pretty good. But ____________ what you bought withthe samples, I don’t think it is __________ the money.

It’s careless _____ him to make the same mistake again. I think it important ______ everyone to be careful in everything.

How far is it from your home to school─It’s fifteen ______ walk.