What’s more, planes or machines produce_____ noise.

Ralph W. Emerson would always ______ new ideas that occurred to him.

With the popularity of the Internet banking, it is becoming more convenient to ________ a business credit card for personal use online.

It’s time________ lessons. But Lily isn’t in theclassroom.

11. When I was sixteen, I had to _________ before graduation and work in a clothes shop to help support my family.