Don't play _____ fire. It's very dangerous. [ ]
A. with
B. /
C. with a
D. with the
答案:A
调制分析的主要局限性是,这种系统基于().
A.静态试验;
B.运动试验;
C.绝对线圈排列;
D.差动线圈排列.
给水泵前置泵的轴端密封是什么型式?