Farmers often employ fertilizer or other special chemicals to _____the growth of crops, as is well-known.

The great achievements in recent 30 years have provedthat the reform and open policy is a vital measure that ________ the nationalconditions of China.

Look, these are ___________ bicycles. They are cool.

56. It is said that some teachers will go to Japan. They are________going to work as exchange teacher of Chinese.

The doctor recommended he ____ a few more days in hospital.