70. I know it is difficult __________ him to talk like the lecturer, but I think he should grasp every chance .
It’s helpful to put children in a situation ____ they can see themselves differently.
Last weekend, I _____ my washing machine ______.
The manager devotes all his spare time ______ the violin.
______ he returns to his native land.
This book _____ ten units, ______ three mainly revision.