His mother _____ teacher.
If I had worked harder at school, I in a comfortable office now.
twice a year, whether it is a car or a bus or a truck, is the rule that every driver must obey in this city.
, he wanted to buy his son a cheap toy for his birthday.
They considered a computer, which was considered a great help in their work.
If we can our present difficulties, then everything should be all right?