滑块为U形时,导向长,承受偏心载荷能力()。
A.弱
B.适中
C.强
D.以上都错
参考答案:C
The research also raises the question ________ children from low-income, less educated families need earlier aid.
A.what
B.that
C.when
D.whether
混凝土喷射作业中,当暂停时间超过( )时,应将仓内及输料管内的干混合料全部喷出。
A.30minB.40minC.50minD.60min