使用喷雾仪护理,应密切观察烧杯中的水位,不能超过水位警戒线,以免出现()现象
A.水溢出烧杯
B.自动断电
C.喷水
D.电热元件烧毁
参考答案:C
The law ________ last month and it is good for everyone. [ ]
A. came into effect
B. had an effect on
C. put into effect
D. affected
在河流水质取样断面处,应按照( )布置水质取样垂线。
A.水深 B.河宽C.流速及水深 D.流速及河道弯曲情况