A number of tests have been conducted to _______ that these drugs have no side effects.
—It’s thirty years since we last met. —But I still remember the story, believe it or not, _______ we got lost on a rainy night.
______ you'll be able to succeed mainly depends on ______ you do and ______ you do it.
What you said just now ____ the matter we are discussing.
A library with five thousand books ______ to the nation as a gift.
The teacher,with 6 girls and 8 boys of her class, __________ visiting a museum when the earthquakes truck.