能表明雷达接收机工作是正常的，下列哪个说法正确（）.
A、有混频晶体电流
B、有磁控管电流
C、旋增益钮屏上噪斑有变化
D、A+C
参考答案：D
(2013·天津高考)If he had spent more time practising speaking English before, he ________ able to speak it much better now.
A．will be
B．would be
C．has been
D．would have been
《资产评估准则——基本准则》由（）发布。
A.财政部资产评估准则委员会
B.国务院国有资产监督管理委员会
C.财政部
D.中国资产评估协会
