压入式局部通风机和启动装置必须安装在（）巷道中。
A.进风
B.回风
C.采区进风
参考答案：A
You can't ____ your book when you are in the exam. Otherwise, you will be punished. [ ]
A. stick to
B. refer to
C. keep to
D. point to
简述燃烧室和烟道的严密性试验有法。
