This old computer must have been of great use to _______ did the scientific research.
The enemies tried to ____ the city, but they failed in the end.
Japan is ____ the east of China, while India is ____ the west of China.
It was stupid ____ him for help. Everyone knows that he is very mean.
It is no ____ arguing with Bill because he will never change his mind.
Joan together with her parents ____ going to visit the Summer Palace this Saturday.