How old is Tom —He is ____.

I am as busy as a bee; you bother me with so many questions now?[ ]

There ______ great changes in our hometownin the past fifteen years.

I used to quarrel a lot with my parents，but now wewell.

Who on earth will take the place of him?— I’m afraid no one would like to ____ the challenge— It’s just too difficult a task. [ ]