下列信号中属于遇险信号的是:()
Ⅰ、每隔1分钟鸣放爆炸信号一次Ⅱ、船上的火焰Ⅲ、以雾号器具连续发声
A.Ⅰ
B.Ⅰ、Ⅱ
C.Ⅱ、Ⅲ
D.Ⅰ、Ⅱ、Ⅲ
参考答案:D
—saw Gina at the party. But she didn't speak to me ______night.
—Maybe she didn't see you. [ ]
A. all
B. every
C. either
D. another
测生水硬度应用()缓冲溶液。
A、氨—氯化铵
B、硼砂
C、醋酸铵