运行中排渣槽的除渣门应经常处于关闭状态，以防冷风漏入炉内。
参考答案：对
When________there, the postman found the door locked and then stopped ______the letter under it. [ ]
A. reaching; to stick
B. reached; to stick
C. reaching; sticking
D. reached; sticking
上腹强烈钝器伤后，X线检查显现腹膜后组织积气，拟诊（）
A.腹膜后十二指肠破裂
B.胰腺断裂
C.胃破裂
D.回肠破裂
E.肝破裂
