21. ---It looks heavy. Can I give you a hand?---_______.
--How dangerous it was ! ---Yes, but for the passer-by’s quick action,the girl _____ .
--Remember the first time we met? ---Sure. You _____ in the supermarket.
Don’t blame them any more---this is _____ because they are still young and lack experience.
_____ the police thought he was the most likely one, since they had no exact proof about it,they had to set him free.
The money collected should be made good use _____ the people who suffered great losses in the earthquake.