Some researchers believe that there is no doubt ____ a cure for AIDS will be found.
When I was a little boy, I lived in a small fishing village. The visit to the village reminded me of the _______ of childhood.
I took a _______ from Beijing to Shanghai last year.
Something must be done to prevent factories ________ poisonous gases so as to keep the city ________.
He was absent for weeks, so he had a lot of homework to ________.
The computer is in ________ bad condition ________ I can’t work with it.