Without facts, we can’t form a correct opinion, for we need to have actual knowledge________ our thinking.
Environment protection requires our joint effort. ______ will be achieved unless we work well together.
---Can I join your club, dad?---You can when you _______ a bit older.
Because the shop_______, all the T-shirts are sold at half price.
---Jack hurt his leg yesterday.---Really?________?
---I love the Internet. I’ve come to know many friends on the Net.---_______ .Few of them would become your real friends.