The science of computer, _____rapid progress has been made in recent years, is the most important of all science.
According to news reports, personal ____ of guns in the USA causes a lot of trouble.
---Did you go to the cinema last night? ---Well, I had ____ to , but it was raining too hard.
Sorry, we are late,--our plane was _____ because of the heavy rain.
I’d like to have visited the Palace Museum, but something unexpected _______ to my father.
-What are you busy with ? -The conference _______ in our city next week.