齿轮模数对齿轮传动有何影响？
参考答案：
模数越大，轮齿越粗状，承受载荷能力越大，如一个齿轮齿数不变，模越大则齿轮的分度圆和齿顶圆也就越大。
词汇运用。
1. The Yellow River is the _______(two)longest river in China.
2. He got a _______ (bad) result in English this term than last term, he didn’t try his best.
3. Do you know which animal has two _______(stomach)?
4. I would like to enjoy the _______(beautiful)of the sunset.
5. Please ask him_______(not watch) too much TV.
6. When I saw this photo, I_______(think)of my uncle.
7.We didn’t enjoy ourselves at the _______(begin) of the trip because of the heavy traffic .
8. Of us all, Kitty has _______(little) money.
9. ______ (join) the school football team, he practises hard even when it rains.
10. Thank you for agreeing_______(let) me go on the class trip, Mr Wu.
男，56岁，进行性吞咽困难2月余，现仅能进食半流质，最可能的诊断是（）
A.食管平滑肌瘤
B.食管间质瘤
C.食管异物
D.贲门失迟缓症
E.食管癌
