The students spent as much time getting trained as they __studyingA were B had C.did选什么 为什么?什么语法现象

The students spent as much time getting trained as they __studyingA were B had C.did选什么 为什么?什么语法现象
The students spent as much time getting trained as they __studying
A were B had C.did
选什么 为什么?什么语法现象

The students spent as much time getting trained as they __studyingA were B had C.did选什么 为什么?什么语法现象
选C,did相当于spent,是为了避免重复