喷射式供油系统中，来自燃油泵的部分燃油导回油箱的作用是：（）.
A.防止腐蚀
B.提高效率
C.提高经济性
D.防止气塞
参考答案：D
Don't forget to bring me a _____. I'll post a letter. [ ]
A. stamp
B. football
C. cake
D. banana
用所给单词的适当形式填空。
1. My friend is _____ (interest) in learning English.
2. _____ (scientist) use English a lot in their work.
3. That translator is _____ (Kate) mother.
4. I want to make friends wish students from other _____ (country).
5. English is the main language_____ (use) by people.
6. I am _____ (wake) all night. I think I am ill.
7. I helped that woman, so I felt very _____ (happy).
8. Jim did _____ (bad) of all in the long jump.
9. Now I feel even _____ (tired) this morning than I usually do.
10. Doing eye _____ (exercise) is good for our health.
