标题: 问道很简单的题，因为以前没人问过。。。 [打印本页] 作者: youwsw 时间: 2011-3-22 15:23 标题: 问道很简单的题，因为以前没人问过。。。 1.As measured by the Commerce Department, corporate profits peaked in the fourth quarter of 1988 and have slipped since then, as many companies have been unable to pass on higher costs. (A) and have slipped since then, as many companies have been unable to pass on higher costs (B) and have slipped since then, the reason being because many companies have been unable to pass on higher costs (C) and slipped since then, many companies being unable to pass on higher costs (D) but, many companies unable to pass on higher costs, they have slipped since then（A） (E) yet are slipping since then, because many companies were unable to pass on higher costs
and 前后时态用法搞不清，可以前面过去式，后面现在完成时的么？作者: clumsy123 时间: 2011-3-22 15:46
我觉得可以的呀~ 因为and后面有个since then，是完成时的标志，所以用完成时