【简答题】We gave out a cheer when the red roof of the cottage came __________ view. A) from B) in C) before D) into
【判断题】在直流电动机起动时,采用电枢串电阻起动,在启动过程中为了快速起动和减小电阻引起的损耗,必须将电阻直接切除掉。
【单选题】他励直流电动机采用在电枢回路串电阻的方法起动时,其目的()。
【单选题】国际邮件外包装选择纸制封套只能封装厚度在( )毫米以内的文件,不得使用旧信封包装。
【单选题】According to the article, when a homeowner puts in a solar roof, her worries about blackouts or power rates might be over. Why might that be true?
A.
Solar power may be less expensive and more reliable than power supplied by utility companies.
B.
Her roof won't leak with the heavy solar panels on top of the roof.
C.
Putting in a solar roof is still an expensive preposition.
D.
Super-efficient appliances use less electricity than regular appliances.
【单选题】直流电动机起动时电流可达额定电流的10-20倍,所以在电枢电路中采用()进行限制。
【判断题】在直流电动机起动时,采用电枢串电阻起动,在启动过程中为了快速起动和减小电阻引起的损耗,必须将电阻直接切除掉。
【单选题】直流电动机起动时电流可达额定电流的10-20倍,所以在电枢电路中采用______进行限制。
【单选题】他励直流电动机采用在电枢回路中串电阻的方法进行起动,在起动时,应将电阻值调至()。