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。 [ ]
