prep1-109 又是并列

109.      (30353-!-item-!-188;#058&004189)

The discovery of glass being expandable and able to be shaped by human breath revolutionized glassworking to such an extent that today "glassblowing" has become the generic term for all glassworking, whether the glass is blown or formed by other techniques.

(A) of glass being expandable and able to be

(B) of glass that is capable of expansion and

(C) of glass being capable of expansion and that it can be

(D) that glass can be expanded and it is able to be

(E) that glass can be expanded and

PREP解释说D and it is able to be 只能跟主句并列怎么理解阿？

没看懂你的意思。

答案是E吗?

D应该属于既wordy又ungrammatical吧，and 后面少了that导致前后unparallel。另外can 和 be able to应该是完全相同的意思，完全可以写成E的形式。

A属于awkward, 而且being后面的由and连接的两个形容词unparallel

B的that是restrictive, 这样一来整句话变成发现一种特别的玻璃了。

C和A错的差不多。

答案是E。

但是prep对D的解释说因为and it is able to be 只能跟主句并列， 而不是和glass can be expanded 并列。怎么能看出来是跟主句并列阿？