问一个关于and 引导的并列句的省略

有见过帖子上说“2个或3个句子并列，第一句有be\become，后面句子中的be\become必须省略，重复的n, adj, conjunction都可以省略”

不过做题时遇到以下两个句子：

1、sb ordered that the levels be measured and the results published

2、a president is likely to be (at a severe disadvantage) and is often unable to (carry out a legislative program).

不知道为什么一个is省略了，一个没有....

谢谢拉~

我刚才问个相似的问题。

看了刘振敏的书，Natural gas is the second biggest fuel source and supplied amost exclusively 的表达是不对的。主系表的BE可以用于省略的被动形式么？ 在我看来前面是现在时态，暗示后面只能是现在时，所以以为是对的。

看来他说的是对的，估计有歧义的BE动词不能省，就算逻辑上能辨别的都不能省。

2如果省了：1.a president is likely to be (at a severe disadvantage) and is likely to be often unable to (carry out a legislative program).

2.a president is likely to be (at a severe disadvantage) and is often unable to (carry out a legislative program).两个意思都可以。

       谢谢你哈，可是我还是不太明白你的解释，不知道为什么第一题的正确答案的省略的，第二题就不省了，把原题贴上，看看我到底错在哪了吧....

1.        Despite protests from some waste-disposal companies, state health officials have ordered
     the levels of bacteria in seawater at popular beaches to be measured and that the results be published.

(A) the levels of bacteria in seawater at popular beaches to be measured and that the results be

(B) that seawater at popular beaches should be measured for their levels of bacteria, with the results being

(C) the measure of levels of bacteria in seawater at popular beaches and the results to be

(D) seawater measured at popular beaches for levels of bacteria, with their results（E）

(E) that the levels of bacteria in seawater at popular beaches be measured and the results

Despite protests from some waste-disposal companies, state health officials have ordered that the levels of bacteria in seawater at popular beaches be measured and the results
     published

我觉得2楼说的蛮好的...主要是从有没有歧义来判断

第一个很明显be done  and be done  第二个be 按gmat的思路就是understood，完全没有歧义

第二个如果省略is ,你说unable是个那个成分并列？是likely 还是at a severe disadvantage呢？不知道... 加上了就是表明是和likely并列

哦，对哈，的确是这么回事，你这么一解释我就明白二楼的意思了~呵呵~

谢谢你们拉~