I have ______ all the papers but I still can’t find my notes.
The girl looked at me with a _______expression. Maybe the problem was quite ______.
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.