I eat lunch _________ my friends.[ ]
A. and
B. with
C. on
D. for
答案:B
下列不等式成立的是( )
A.log0.30.6>1
B.log32<0
C.0.73>0.63
D.log0.52<log0.53
两端锭接的压杆,其临界力计算公式为()
A.
B.
C.
D.