使用敞车装载钢板，长度（）的钢板允许中部搭头，两端紧靠车端墙。
A、7m～8m
B、8m～9m
C、7m～9m
D、7m～10m
参考答案：C
John, who is seventeen this year, usually eats ____ his father does. No wonder he is growing taller. [ ]
A. twice more than as much as
B. more than twice as much as
C. twice as much as more than
D. twice as more than much as
H2S与空气作用，可生成危害更大的（）。
A、SO2
B、SO3
C、H2SO4
D、S
