城市污水处理中的一级处理要求SS去除率在（）左右。
A、30%
B、50%
C、20%
D、75%
参考答案：B
以“语不惊人死不休”为艺术追求的唐代诗人是 __________ 。
Reportedly, yesterday a group of American soldiers were walking along the road in Iraq when a bomb was _______, three of whom were killed.
A．set off
B．set out
C．set up
D．set about
