Do ____ you think is right, ____ difficulties you may have.
There are more opportunities for disabled people to make______ contribution to______ society.
---What’s wrong with my stomach? ---There is nothing serious; you can __________.
It was the training _____ he had as a young man _____ made him such a good engineer.
It was not until he came back _____ he knew the police were looking for him.
I hate _____ when the light turns red and the people don’t move until it is about to turn green again.