请教GWD一语法题

zhengshaobo

Antarctica receives more solar radiation than does any other place on Earth, yet the temperatures are so cold and the ice cap is reflective, so that little polar ice melts during the summer; otherwise, the water levels of the oceans would rise 250 feet and engulf most of the world’s great cities.

is reflective, so that little polar ice melts during the summer; otherwise,
is so reflective that little of the polar ice melts during the summer; were it to do so,
so reflective that little polar ice melts during the summer, or else
reflective, so that little of the polar ice melts during the summer, or
reflects so that little of the polar ice melts during the summer; if it did
答案选B，
但是B里面有一个不懂的地方是，yet the temperatures are so cold and the ice cap is reflective that little of the polar ice melts during the summer; were it to do so,中“and”连接了两个主谓结构。那是不是and前面要用逗号隔开呢。 不是说and 是不能连接两个主谓结构的吗？

请高人指点一下

weirui5621

我也很纳闷呢，刚做了这一题，在BC里犹豫了很久

B好在后面是虚拟语气，和would rise对应
但是没有,真的很奇怪。

希望NN指点

weirui5621

http://forum.chasedream.com/GMAT_SC/thread-79677-2-1.html

这个讨论的12楼rhod的解释是我比较赞同的，lz可以参考

zhengshaobo

那个解释确实不错，但是似乎不能回答我上面提的问题，关于“and” 能否连接两个主谓结构，且没有逗号隔开的情况下。

weirui5621

lz 我认为这里没加逗号是有道理的。

the temperatures are so cold and the ice cap is so reflective that little of the polar ice melts during the summer 这里两个so一同和后面的that搭配

如果这里加了逗号：the temperatures are so cold， and the ice cap is so reflective that little of the polar ice melts during the summer 会改变原意的，可能只是后面那个so reflective和that搭配，与前面的so cold没有关系，句子的联系被逗号断开了。

这里不加逗号是为了保证句子的前后联系，加上后会造成歧义