4. I think the _____ invention is a mobile phone. What about you?

　 A. helpful　　 B. more helpful　　 C. helpfulest　　　 D. most helpful

3. Can you tell me _____ the train was invented?

　 A. what　　　 B. who　　　　　　 C. when　　　　 D. which

2. Was a car invented _____ March 4, 1876?

　 A. on　　　　 B. in　　　　　　 C. at　　　　　　 D. of

1. What is a telephone used _____, class?

　 A. to　　　　　 B. in　　　　　　 C. for　　　　　　 D. about

10. We took the pictures with the new c_____ last month.

9. A machine is made of m_____.

8. Salt is p_____ in East and South China.

7. He was wearing a new cap, but I didn’t even n_____ it.

6. Have you b_____ the baby’s milk yet?

5. The soup isn’t s______. Put some salt again, please.