government bans on the dumping of sludge anywhere in the ocean are based on the belief that the spread of sludge by ocean currents poses a danger to people.since it is not clear that sludge dumped on the ocean bottom, far from coasts,would endanger people, the bans should be revised to apply only to coastal waters
each of the following, if true, supports the conclusion that the bans on ocean dumping should be revised except
D)dumping large amounts of sludge would have an unknown effect on organisms that live on the ocean bottom.
E)the technology exists to lower sewage sludge to ocean bottom dump sites without contaminating waters closer to the surface.
答案D
不好意思，打字慢了，就只把我有疑问的发出来了.
E)既然有这种技术可以不让表面的水受到污染，那么不是就不用ban了吗？不就不支持conclusion了吗。所以我就认为E 也是对的，谢谢各位了作者: xiangxiangling 时间: 2010-5-7 21:39
