It suddenly to the teacher that he hadn’t left any assignments(作业) to his students.
—Why does the lake smell terrible? —Because large quantities of water .
—Hi, Tom, why are you looking so tired? —I'm tried. Because I ______ the living room all day.
__________ is troubling me is __________ I don’t understand __________ he said.
______________________, I would have given you his address.
As a teacher, he knows exactly how to his ideas to the students.