求问一个题目OG2017 780题

熊猫团子君

Construction of the Roman Colosseum, which was officially known as the Flavian
Amphitheater, began in A.D. 69, during the reign of Vespasian, was completed a
decade later, during the reign of Titus, who opened the Colosseum with a onehundred-
day cycle of religious pageants, gladiatorial games, and spectacles.
(A) which was officially known as the Flavian Amphitheater, began in A.D.
69, during the reign of Vespasian,
(B) officially known as the Flavian Amphitheater, begun in A.D. 69, during
the reign of Vespasian, and
(C) which was officially known as the Flavian Amphitheater, began in A.D.
69, during the reign of Vespasian, and
(D) officially known as the Flavian Amphitheater and begun in A.D. 69,
during the reign of Vespasian it
(E) officially known as the Flavian Amphitheater, which was begun in A.D.
69, during the reign of Vespasian, and

这个题目正确答案是C，应该是说这个Construction开始于和完成于，两个动词并列。
我只是有个问题是，为什么并列的两个动词，而且开始和结束属于同一性质的动词，一个用了被动一个没有用？
在版面上没有看到解答，还希望各位大大帮忙看看~谢谢！

Ivy吕

construction 开始于一个时候，不用被动说被开始，但是construction 必须是被完成，而不是结束，所以你这个结束于让你迷糊了。

熊猫团子君

谢谢~！

Fiona09

引用版上Helr老师的解释：

其实用began和was begun都可以的。有很多词，主动和被动是同意的。

比如，the door is opened和the door opens。理论上，门也不能自己开，怎么也是被风吹开的。。

begin也是一样的道理。

熊猫团子君

求个指点~是不是太简单了。。都没人肯回。。。