空压机每运行()小时检查气缸、排气阀一次。
A.50~100
B.100~150
C.150~200
D.200~250
参考答案:B
Mr. Smith couldn’t open the door because his naughty boy _______ it from the inside
A.would lock
B.was locking
C.has locked
D.had locked
清热燥湿又能退虚热的药物
A.黄芩B.黄连C.黄柏D.苦参E.龙胆草