[文法] 文法錯在哪？

[k66k66 (k66)]

The residual energy of the sun is so low in the outer solar system that an
                                                                   ^^^^^^^
                                                                      A

ocean to exist would require some other source of energy to keep it from
               ^^^^^         ^^^^                           ^^^^^^^
                 B             C                               D

freezing solid.



A, B, C, D選項中有一個是錯的
我想應該是A或B錯
A應該要改成that "for" an ocean to exist...
但是這樣的話B還是怪怪的

請問要怎麼改比較好？

謝謝

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◆ From: 123.192.150.144
→ dunchee:"A ..."-> Yes.  //"...B.."-> 哪裡怪?
→ dunchee:http://www.ldoceonline.com/dictionary/would
→ dunchee:->2 ....
→ k66k66:謝謝d大！關於B, 我以為要改成for an ocean to exist, some
→ k66k66:other source of energy to keep it from freezing solid
→ k66k66:would be required. 會比較好。
→ czr:是不是D錯了﹐keep改為prevent