请问prep1 的154题

咕嘟pp

154.
Some patients who do not respond to therapies for depression may simply have received inadequate treatment, having, for example, been prescribed a drug at a dosage too low to be effective or having been taken off a drug too soon.

(A) having, for example, been prescribed a drug at a dosage too low to be effective or having been

(B) having, for example, a drug prescription that was ineffective because the dosage was too low, or being

(C) as, for example, having too low of a dosage of a prescribed drug for it to be effective, or being

(D) when they have, for example, been prescribed too low a drug dosage to be effective, or were

(E) for example, when they have a drug prescription with a dosage too low to be effective, or been

答案是A，但A不是having been done 了吗？？
答案的解析说这个have是个实义动词，但我没理解，是实义动词了怎么翻译啊？
请教NN们

deer321

http://forum.chasedream.com/GMAT_SC/thread-333175-2-1.html

deer321

uppp

Gisele09

顶~同问~
之前一直都是看到having been就排除的，难不成排错了？？？

咕嘟pp

ding ding。。 希望可以得到解答。
为什么这题having been done对了？？

咕嘟pp

非常感谢，只是我一直认为having been done这种完成进行时用法是错的，所以一看见就把A排除了，这个是完成进行时吗？

fwj34

这题考的是or前后时态的对应，你看or后面是having been的前面就也要这样，其他的时态都不对，唯一可能一致的是C,出现了BEING,排除了。

希望能帮到你并祝你取得好成绩！