This old sweater doesn't the cold. [ ]
A. keep from
B. keep away
C. keep
D. keep out
答案:D
在后张法施工中,下列适用于单根粗钢筋的固定端锚具是()。
A.螺丝端杆锚具
B.镦头锚具
C.单根锥销夹具
D.单孔夹片锚具
气相色谱法测定水中有机磷农药时,为什么敌百虫要轩化成敌敌畏间接测定?