大全 446 求助

It may be another fifteen years before spacecraft from Earth again venture to Mars, a planet now known to be cold, dry, and probably lifeless.

(A) again venture to Mars, a planet now known to be

(B) venture to Mars again, a planet now known for being

(C) will venture to Mars again, a planet now known as being

(D) venture again to Mars, a planet that is known now to be

(E) will again venture to Mars, a planet known now as being

答案是A, 用分词短语修饰同位语a planet. 为什么用定语从句修饰a planet的D不对?

D.  1. that is 省略后不影响句意，所以应该省略。

2. now 的位置错， known now to be 错， now known to be 才对呀。

参阅：【讨论连接】GMAT语法讨论汇总

请问venture为什么不加s? Spacecraft应该是单数吧？

spacecraft are vehicles used for flight in outer space.

                                       ______来自牛津例句

通常spacecraft 是单数,谓语venture应该是单数ventures.但该句为虚拟语气, 省了would.