Look! My glasses ___________ on the table. [ ]
A. is
B. am
C. are
答案:C
目前允许作为气雾剂的抛射剂的是()
A.Freon
B.二甲醚
C.四氟乙烷
D.七氟丙烷
E.Azone
五气之“湿”属于
A.木B.火C.土D.金E.水