题目内容：

Mr. Clark works in a middle school. He likes reading and often borrows some books1.the library. He listens to the radio every morning and reads newspapers after supper. So he knows much and teaches well.

Mr. Clark has a nine-year-old son, Mike,2.also likes reading books. And he often asks his father some questions. Mr. Clark always thinks he’s too young3.(understand) him and chooses the easiest ones to answer. Of course the boy is not satisfied with it.

On day Mike read something about lights and was4.(interest) in it. He asked his father a few questions, and without any5.(difficult) his father answered them all. Then his father said6.(proud), “Fathers always know   7.(much) than sons!” The boy thought for a while and said, “I don’t think8..” His father asked, “oh? Why?” Mike didn’t answer, and asked instead,  “Who9.(invent) lights in the l9th century?” “Thomas Edison,” answered Mr. Clark. “why didn’t his father invent them, then?”10.(look) at his son, Mr. Clark didn’t know what to say!