—Why are you looking so worried? —I sent an email to my son in America last week, but no reply ________.
—Sorry, I made a mistake again. —______. Practice more and you’ll succeed.
I’d like to ______ you _______ your success on the experiment.
It is generally believed that teaching is ______ it is a science.
He raised his voice to make himself _______ clearly by the audience.
There were too many people in the room and he could hardly find a chair ______.