—I apologize for not being able to join you for dinner.—________.We’ll get together later.
By the time he arrived in Beijing, we _______ there for two days.
The professor could hardly find sufficient grounds________ his arguments in favor of the new theory.
Along with the email was my brother’s promise ______ I came first in the competition, he would buy me an MP4.
"We can’t go out in this weather," said Bob, ________ out of the window.
Scientists are convinced _______the positive effect of laughter ______ physical and mental health.