请问一个白勇语法书上面的题

redjean

The development of a new jumbo rocket that is expected to carry the United States into its next phase of space exploration will be able to deliver a heavier load of instruments into orbit than the space shuttle and at a lower cost.
A)    The development of a new jumbo rocket that is expected to carry the United States into its next phase of space exploration will be able to deliver a heavier load of instruments into orbit than the space shuttle and at a lower cost.
B)    The development of a new jumbo rocket  is expected to carry the United States into its next phase of space exploration and be able to deliver a heavier load of instruments into orbit at a lower cost than the space shuttle.
C)    The new development of a jumbo rocket, which is expected to carry the United States into its next phase of space exploration, will be able to deliver a heavier load of instruments into orbit at a lower cost than the space shuttle.
D)    A newly developed jumbo rocket, which is expected to carry the United States into its next phase of space exploration, will be able to deliver a heavier load of instruments into orbit than the space shuttle can, and at a lower cost.
E)    A newly developed jumbo rocket, which is expected to carry the United States into its next phase of space exploration, will be able to deliver a heavier load of instruments into orbit than the space shuttle and to cost less.
答案是D，但是我觉得D里面最后一句and at a lower cost怎么看都不顺眼，我想问问如果and连接的是两个句子，然后把主语和谓语都省略了，但是并列句里面能这么省略吗？如果at a lower cost只是做状语，状语前面可以有and吗？

不好意思标题不符合规范。

Snazzy

not parallel, why?

redjean

什磨意思啊

thornbirdcfa

．．will be able to deliver a heavier load... , and at a lower speed. and后可以这样省略．
比较看看：81.In 1973 mortgage payments represented twenty-one percent of an average thirty-year-old male’s income; and forty-four percent in 1984.　

[此贴子已经被作者于2004-1-7 13:34:27编辑过]