标题: but需不需要像and一样前后平行 [打印本页] 作者: IWANT750 时间: 2016-11-29 23:28 标题: but需不需要像and一样前后平行 17. Sunspots, vortices of gas associated with strong electromagetic activity, are visible as dark spots on the surface of the Sun but have never been sighted on the Sun's poles or equator.
a. 如原题
b. are visible as dark spots that never have been sighted on the surface of the Sun
c. appear on the surface of the Sun as dark spots although never sighted at
d.appear as dark spots on the surface of the Sun, although never having been sighted at
e. appear as dark spots on the Sun's surface, which have never been sighted on
正确选A
请问but后面的have never been sighted on是和前面的are时态不一样啊。不需要平行吗这里？ 作者: Fiona09 时间: 2016-11-30 11:37
这里从句意上来说是平行的，但结构上确实是时态用得不一样。
非牛牛，但我觉得这里一般现在时和现在完成时并列是没有问题。两个都是表示一个客观存在的情况，意思是以黑点形式在太阳表面可见，但从未在太阳的两极或赤道被发现。作者: GMAT♠ASSASSIN 时间: 2016-11-30 11:55
tense is not required to be same in terms of parallelism. There are many officially correct answers demonstrasting this point already.
OG17#700
The widely accepted big bang theory holds that the universe began in an explosive instant ten to twenty billion years ago and has been expanding ever since.作者: IWANT750 时间: 2016-11-30 14:20
GMAT♠ASSASSIN 发表于 2016-11-30 11:55
tense is not required to be same in terms of parallelism. There are many officially correct answers ...