I ______ in Tibet for three years; if you go there for your holiday this summer, I’ll have my friends take care of you.
Would you please ______ your statement again? I don’t understand what you were saying.
---How long has the United Nations ________? --- ______1945.
Dr. Black is a professor of chemistry. _______, he is a famous writer.
The new invention may __________a lot of changes in our daily life.
It _______ them three years to build this road.