PRS700/+24V系统分流器是安装在()
A.正极
B.负极
C.以上都不是
参考答案:B
—Hurry up!Alice and Sue are waiting for you at the school gate.
—Oh!I thought they______without me.
A.had gone
B.are going
C.have gone
D.went
在描述行研究中,研究资料的主要分析指标是____________。