MF30型万用表采用的是( )测量机构。
A.电磁系
B.感应系
C.磁电系
D.电动系
参考答案:C
—Is there any possibility you could pick me up at the airport ?
—No problem.
A.when
B.that
C.whether
D.what
叶序分为哪几种形式?