Our teacher told us that light ______ faster thansound.

The reason ___ he can’t come is ______ hehas to work late.

It sounds like something is wrong with the car’s engine.______, we’d better take it to the garage immediately.

.If you compare food costs today ______ of a year ago, you will find the difference

ll my attention _______ my homework, I didn’teven notice my father standing by me.