—Mary, do you still remember the first time we met?—of course, You Helen’s birthday party with your friends in a restaurant.
Rock climbing is ___ great fun. You will get close to ____ nature and take adventures at the same time.
— In order to improve your English, you need to practice more. — ______. Practice makes perfect.
How the fire in the dancing hall started _________ a mystery.
Please don’t try to back out _____ everything has been arranged.
Simon is very regretful. If he had been more careful, he _____ such a big mistake.