The 2010 World Cup will be held in South Africa, and no one can _____which country will be the champion. [ ]

________ is known to everybody, Taiwan is a part of China. We must unify it.

Think twice before you others’ cheating in the exam, because you are not going to help butindeed to kill their motivation for study.[ ]

You look so tired.— ________ I ran for two hours.

Don’t _______ your grandmother. It’snot polite.