自凝树脂的引发剂含量一般为聚合粉重量的
A.1%
B.0.5%
C.5%
D.0.1%
E.2%
参考答案:A
把7个相同的小球给3人,每人至少1球则不同的给法为( )
A.4
B.10
C.15
D.37
— Why does the lake smell terrible?
— Because large quantities of water _________.[ ]
A. have been polluted
B. has polluted
C. have polluted
D. has been polluted