His pale face suggested that he _________ frightened.
It sounded like a good idea, but _______it didn’t work.
The quality of the goods in this firm is _______ to the customers, as there has been no complaint since it was founded.
After he retired from office, Tim ________ painting for a while, but soon lost interest.
China has seen _______dramatic decline in rural poverty, but the problem is on _______increase in Africa and South Asia.
Happiness often comes to those try to help others and do something worthwhile. A whom B. who C. what D. which