[求助]一题

ninaluan

( 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.)

D. a newly developed jumbo rokect, which is expected to carry the untied states into its next phase of space exploration, will be able to deliver a heavier load of instruments into orbit than the space suttle can, and at a lower cost.

E.. a newly developed jumbo rokect, which is expected to carry the untied states into its next phase of space exploration, will be able to deliver a heavier load of instruments into orbit than the space suttle and to cost less.
请问E错在哪里？谢谢！

joywzy

If E states
E.. a newly developed jumbo rokect, which is expected to carry the untied states into its next phase of space exploration, will be able to deliver a heavier load of instruments into orbit and to cost less than the space suttle .

i think E is ok.But E omits the comparison of rocket after the word of "less".