_______of the students ______girls in our class.

A．Two percents; is

B．Twenty percents; are

C．Two percent; are

D．Twenty percent; is

状况良好的设备接地引下线导通测试值应在（）以下。

A.50mΩ

B.80mΩ

C.100mΩ

D.120mΩ