When she was in trouble, I did what I could to help her. my help, she wrote me a letter of thanks.
Children’s brains can’t develop properly_______ they lack protein(蛋白质).
______ I had done it I knew I had made a mistake.
Elbert Einstein, for ______ life had once been very hard, was successful later in science .
You are really very kind. I’ll never forget the you have done to me.
It was quite a long time I made it out what had happened.