电流互感器的变流比为一次绕组的额定电流与二次绕组（）之比。

A、最大电流

B、最小电流

C、额定电流

D、负荷电流

小题1: Please turn down the TV a little. It’s too noisy to make __________ (we) heard.

小题2:Last week, Miss Brown was robbed of her necklace. Now when Miss Brown closes her eyes,

one of the __________ face comes into her mind. (rob)

小题3:The old scientist died in his__________ (ninety).

小题4:With the money we have __________ sent many poor children to school.(success)