20 GWD17-Q20:

Construction of the Roman Colosseum, whichwas officially known as the Flavian Amphitheater, began in A.D. 69, during thereign of Vespasian, was completed a decadelater, during the reign of Titus, who opened the Colosseum with a one-hundred-daycycle of religious pageants, gladiatorial games, and spectacles.

Began和wascompleted是句子的谓语，需要并列

A.   which was officially known as the FlavianAmphitheater, began in A.D. 69, during the reignof Vespasian,

B.   officially known as the FlavianAmphitheater, begun in A.D. 69, during the reignof Vespasian, and

C.   ！which was officially known as theFlavian Amphitheater, began in A.D. 69, during the reign of Vespasian, and

D.   officially known as the Flavian Amphitheaterand begun in A.D. 69, during the reign ofVespasian it

E.    officially known as the FlavianAmphitheater, which was begun in A.D. 69, duringthe reign of Vespasian, and

答案选C 我选的B 为什么C的前面began用主动语态 后面was completed用被动？

求助

理解楼主。
这是英文的习惯。就背一下吧。I complete/It is completed. 真的很少看begin用被动。