车辆制动装置中，（）是连接相邻各车辆的制动主管，能在列车通过曲线或车辆互相伸缩时，保证压缩空气的畅通。
参考答案：制动软管
用所给动词的适当形式填空。
1. They are trying______(save) the boy by doing everything.
2.—Why not______ (have)a rest?
—Good idea.
3. You'd better______ (not play) football in the street.
4. When they______ (find) the lost child, the mother was very grateful.
5. He used to______ (take) a walk after supper.
6. They are used to______ (quarrel) with each other.
7. When the police arrived, the wounded (send) to the hospital.
8. If you are too lazy, you______ (not pass) the exam.
9. Jim said he ______ (come) from the USA.
10. Look! There is a cat ______ (climb) up the tree.
球菌性口炎的病因是（）。
A.细菌感染
B.真菌感染
C.自身免疫功能缺陷
D.变态反应
E.病毒感染
