长钢轨装车时，轨端要平齐，伸出承轨横梁（）。
参考答案：0.5-1m
“Could you do me a favour and take the box up to the six floor?” “_______.”
A．With pleasure
B．My pleasure
C．No wonder
D．No comment
矩形ABCD中,对角线AC、BD相交于点O,∠AOB=2∠BOC.若AC=18cm,则AD=_____cm.
