用所给单词的适当形式填空：Keep ____(study) hard,and you will catch up with others.

用所给单词的适当形式填空：Keep ____(study) hard,and you will catch up with others.
Do you know where _____(find) the photos that you _____(take) in Beijing?
Wouid you like a hand _____(finish) the work?
The digital camera is too expensive _____(repair).
the book that ____(buy) yesterday is really hard ______(understand).