重大危险源是客观存在的危险物质或能量超过()的设备设施。
A.500卡
B.1000卡
C.一定量
D.临界量
参考答案：D
小题1:He ▲ off the bike when he was riding it.
小题2: I'm not sure which hair style ▲ me best.
小题3: He got up early this morning ▲ the first bus.
小题4:Sally, go and see who ▲ on the door.
小题5: You should study hard, or you ▲ many good chances.
IMViC试验不包括（）
A.糖发酵试验
B.吲哚试验
C.枸橼酸盐利用试验
D.甲基红试验
E.VP试验
