家长否定心理根源是什么?()
A.负面的教育习惯
B.负面的思维习惯
参考答案:A, B
—What should I wear for the party, darling?
—_______.We're already late!
A.Come on!
B.Cheer up!
C.It's a long story.
D.Don't mention it
由于直流电机电刷压力没有在工艺要求范围内,因而引发在运行中电刷下火花过大,一般要求电刷压力为()kPa。
A.0.05~0.15;
B.0.15~0.25;
C.0.2~0.25;
D.1.5~2.5。