He could speak English fluently because he __________ it for four years when he was a college student.
Their plan was ____. With it we had little trouble in finishing the work.
When we heard the gun fire, we all stood still and shook with _______.
The room ______ white last year is my study.
---_______ leave at the end of this month. --- I don’t think you should do that until ____ another job.
Is it a wonder that little cells can store much energy?