—Look at the black clouds.It__________soon. —Sure.If only we__________out. A.is raining;didn’t come B.is to rain;won’t start C.will rain;haven’t started D.is going to rain;hadn’t come
【简答题】题示为某冲床机构, L AB =100mm, L CD =125mm, L BC =400mm, L CE =450mm, L AD =410mm, AB 为主动件,并绕 A 点作匀速转动,试分析并回答: ( 1 )从运动形式的转换角度分析,该组合机构能实现将主动件的 ______________ 运动转换成从动件的 ______________ 运动;它由曲柄 _______________ 机...