A:苏联国际主义的援助
B:社建总路线的鼓舞
C:人民公社化运动的激励
D:“大跃进”“以钢为纲”的号召
① {m⊥αn⊥α ⇒m//n ;② {m⊥αm⊥n ⇒n//α ;③ {m//αn//α ⇒m//n ;④ {m⊥αn//α ⇒m⊥n .
其中正确命题的序号是( )
计算:3x3•x等于( )
It's________of him to set his aim high but do little,so he is always leaving things undone.