掩护式液压支架由哪些主要部分组成?
参考答案:
掩护式液压支架由顶梁、掩护梁、侧护护板、前后连杆、底座、推移机构、支柱、平衡千斤顶和液压控制系统等10部分组成。
I said hello to her with a smile in the yard, but she ________ me.
A.settled
B.injured
C.ignored
D.shocked
为了减轻火花放电和感应带电的危险,可采用阻值为( )Ω的导电性工具。
A.70~100
B.90~100
C.100~107
D.107~109