Criticism and self-criticism _____ necessary _____ it helps us to correct mistakes.
John _______ for London this afternoon and his flight _______ off at 18:20.
It is Ms Chen’s serious attitude________ her work and her interesting methods of teaching that make us like her very much.
The_______ moment we had been looking forward to_______ last week.
The number of deaths from heart disease will be reduced greatly if people_______ to eat more fruit and vegetables.
In the beginning,the man refused to say anything about the lost car,but he had to admit ________ it because of the solid proofs.