工件在两顶尖间装夹时,可限制()自由度。
A、四个;
B、五个;
C、六个;
D、三个
参考答案:B
—Tom, how do you practice your spoken English?
— Oh, I do it reading aloud every morning.
A.for
B.with
C.by
D.at
建筑幕墙锚筋严禁使用( )。
A.HPB235B.HRB335C.HRB400D.冷加工钢筋