熔断器是利用熔体的()作用切断电路的。
A.熔化
B.阻断
C.电阻
D.超压
参考答案:A
— Mary, would you like to _____ this game?
— I'd love to, but I have to finish _____ the composition first. [ ]
A. join in, to write
B. attend, writing
C. join, to write
D. take part in, writing
利用加法结合律可以使一些运算简便。 [ ]