——What is the man over there? ——I don’t know for sure. But I think he can be ____ but a teacher.
_____ you make a promise, you should keep it.
Every time ______ they met, they would talk several hours together about the persons and things _______ they remembered in the middle school.
My boss insisted that I _______ the work before ten o’clock tonight.
The country has _______ great changes and become a developed one.
We are often _____ by the doctors to eat more healthy food and take plenty of physical exercise.