Ⅱ. 用括号里所给单词的正确形式填空
【小题1】It's ____________（danger） to play with fire.
【小题2】There's a chance of rocks ____________（fall）. Please be careful,
【小题3】I'll ask my father ____________（help） you tomorrow.
【小题4】We should try our best ____________（keep） our classroom clean.
【小题5】Let me ____________（introduce） myself.