[問題]TT GWD 2-34

[小小白]

NASA’s methodical approach to the exploration of Mars has not yet answered the questions of whether biological life forms ever emerged on Mars[i] and whether, presuming such life forms having left fossil traces to begin with, those traces can [/i]still exist in some moist recesses of the cold and arid planet.

A.and whether, presuming such life forms having left fossil traces to begin with, those traces can
B.and whether, if it is presumed that such life forms left some fossil traces to begin with, can those traces
C.and whether, presuming such life forms left fossil traces to begin with, those traces
D.and, presuming such life forms did leave some fossil traces to begin with, if they can
E.and, presuming such life forms to have left fossil traces to begin with, if they

這題排除其他選項後,剩A,C的. A跟C的差異是 having left/left, those traces can/those trace. 我選C,但答案是A. 不太懂,為何一定要用完成式與助動詞can呢?

[dibert8]

(C) 流水句

[bonus]

請原提問者註明
是GWD 滔滔31裡的
TT GWD02
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謝謝

[!阿斯拉]

(C) 流水句

dibert8大大 請問流水句的意思是??

[chaosmaster]

(C) 流水句

dibert8大大 請問流水句的意思是??

一個句子兩個動詞

[dibert8]

不好意思! 改選 (C) 了
(A) 的 having 用法不好,應該用子句
(C) 省略 that; 想了一下時態,應該是對的.

[hwatai]

C吧～

A的having的確不好