坍塌险情的抢护方法是什么?
参考答案:
①护脚防冲法;
②沉柳护脚法;
③桩柴护岸(散厢)法;
④柳石软搂法;
⑤柳石搂厢法。
It's so noisy. I'd really appreciate ______ if you'd turn the radio down.
[ ]
A. that
B. it
C. this
D. which
计算题:一台电动机的功率P为1.1kW,接在U=220V的交流电源上,工作电流I为10A。试求电动机的功率因数cosΦ为多少?