Many things that people use each day started with a simple （简单的）idea.These things have often __31___ the way we 31 live.Some help us to do a job more ___32__ .Others help us to fill a need or ___33___a problem.
In 1858 Lipman had such an 33 idea.One day he took 34___a pencil,a piece of paper,and an eraser.34 Then he began to write.Sometimes he __35___ to change a 35 word.Each time he had to ____36____under his books and papers to 36 find the eraser.“ I wish my eraser would stay in one ____37____!” he thought to himself.
Then Lipman had his simple idea.He cut a ___38___ in one end of the 38 pencil.He glued （粘）the eraser into this groove（沟槽）.Later he thought that 39 others might ___39__ to have such a pencil.So he sold his design(设计).Soon pencils 40___ erasers came into use.Some pencils with erasers were 40_____.His design helped him make lots of money,he got $100,000.
31.A.shown B.found C.changed D.pointed
32.A.easily B.clearly C.luckily D.carefully
33.A.discuss B.study C.offer D.solve
34.A.back B.out C.away D.off
35.A.began B.failed C.refused D.needed
36.A.search B.see C.hide D.move
37.A.side B.box C.place D.space
38.A.hole B.groove C.mark D.crossing
39.A.agree B.forget C.like D.mean
40.A.with B.without C.or D.and