使8051的定时器T1停止定时的指令是()。
A.CLRTR0
B.CLRTR1
C.SETBTR0
D.SETBTR1
参考答案:B
_____ in the queue for an hour,Tom suddenly realized that he had left his wallet at home.
A.To wait
B.Have waited
C.Having waited
D.To have waited
一螺线管型电感线圈因受潮而使线圈平均直径增加,则电感量()。
A、不变
B、减小
C、增加