铁路信号设备是()、()和()的总称。
参考答案:铁路信号;联锁设备;闭塞设备
Miss Gao is ______ to music. She spends a lot of money ______ CDs. [ ]
A. to listen; to buy
B. listening; buying
C. listening; to buy
D. listen; buy
清除脐部污垢通常用
A.洗必泰
B.酒精
C.肥皂水
D.乙醚
E.汽油