井下有毒有害气体有() ["一氧化碳","二氧化硫、硫化氢","甲烷","氨气、氢气"]
对钻孔灌注柱进行成孔检测时,其沉渣厚度应()。 ["<700mm","<500mm","<400mm","<300mm"]
We must()that the experiment is controlled as rigidly as possible. ["assure","secure","ensure","issue"]
什么叫做谱表?
电动执行器的电机有()个绕组,当其中一个为()绕组时,另一个为()绕组。
DEH系统电液转换器小滑阀各线圈阻值约为:控制线圈(),振荡线圈(),反馈线圈()。