研究表明,人体对()有较强的吸收能力。
A.可见光
B.近红外线光
C.远红外线光
D.紫外线光
参考答案:C
On rainy days, the umbrella is used rainwater off. [ ]
A. for keep
B. for keeping
C. keeping
蒸汽套法就是在构件模板外再用一层紧密不透气的材料做成蒸汽套,气套与模板间的空隙通常约为()
A.50mm
B.100mm
C.150mm
D.200mm