Question

The 30th olympic games,offically__as "London 2012 oympic games",

will take place from July 27 to august 12.这题为什么用known?谢谢

Answer 1

这题为什么用known?
因为 known as "被称为" , 是固定搭配,又是过去分词短语作定语修饰The 30th olympic games, 相当于一个非限制生性定从:
The 30th olympic games,offically__as "London 2012 oympic games",
=The 30th olympic games,which was offically ( known ) as "London 2012 oympic games",
句意: 第30届奥运会, 被官方称为"伦敦2012届奥运会" , 将于7月27至8月12日举行.

Answer 2

因为后面有as，否则可以说offically called "London 2012 ……