.It is very difficult to his mind because he is always changing his mind.
I began to fish before memory began, _______ I know I have always fished.
______ 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 .
In my opinion, all Mr Tom ______ good to his students in his class at present. He is very strict in their study.
--- Can you attend tomorrow’s meeting? --- I am sorry, but I will have too much work ______.