关于完成时在平行结构中的疑惑

jay871750293

115. (30629-!-item-!-188;#058&004284)

Many population studies have linked a high-salt diet to high rates of hypertension and shown that in

societies where they consume little salt, their blood pressure typically does not rise with age.

(A) shown that in societies where they consume little salt, their

(B) shown that in societies that have consumed little salt, their

(C) shown that in societies where little salt is consumed,

(D) they showed that in societies where little salt is consumed,

(E) they showed that in societies where they consume little salt, their

OA: C

154. (33193-!-item-!-188;#058&006626)

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

        OA: A
疑惑：have done and have done的平行结构中，第二个have可以省略吗？

迷惑中，谢谢大家指教~~~

jay871750293

可以，因为不会让人觉得confused。

-- by 会员 Serena0710 (2012/4/15 20:33:04)

恩，好的，谢谢咯~~~

Serena0710

可以，因为不会让人觉得confused。

曲比欣

同问啊~~

jay871750293

木有人诶，自己顶一下！