肾移植供者最佳年龄为（）。

A.50～60岁

B.>60岁

C.40～50岁

D.30～40岁

E.20～30岁

根据句意及所给中文提示或英文解释，写出句中所缺单词，每空限填一词。

小题1:Keep a        (微笑) all the time, you’ll have a happier life.

小题2:The weather report says it will be           （有雨的）. Please take an umbrella with you.

小题3:Drivers should          （停车）their cars in the right place, or they will be fined.

小题4:Audrey Hepburn had put her           （努力） into ballet training before she entered the film industry.

小题5:Daniel’s        （努力）is to be a famous director in the future.

小题6:Zhang Sen was a brave young man. He _________(keep somebody safe from danger)a young lady from a river several months ago.

小题7:Our teachers are          (treating every person equally) to everybody in our class. We all love them.