19.The Greens chose to live lift was cheap,and they moved to a small town years ago.
A.if B.until C.when D.where
20.I wrote a letter to the car dealer, what had happened to my new car.
A.explaining B.to explain C.explains D.explained
三、完形填空（共15小题：每题2分，共30分。）
通读下面的短文，掌握其大意。然后，从每小题的四个选择项中选出最佳选项。
Everyone likes things that are free,and businesses ofter givethings for free to customers as a way of getting more people to pay attention to their products.
Ariely,a scientist from MIT,did an experiment on what people woulk do when 21 things that were free.He 22 a group of students two kinds of chocolates:the good one for 15 cents was very cheap, 23 the poor quality chocolate was worth 5 cents,so 24 it for I cent wasn’t very cheap.
Most people chose the high quality chocolate for 15 cents.That’s not a 25 .But then Ariely lowered the 26 of both pieces of chocolate by I cent.If People were 27 correctly,then they shoule 28 choose the good quality chocolate.But that 29 what happened.Most people chose the free chocolate.This doesn’t make sense in our 30 way of understanding economic behavior（经济行为）.
What is happening here?Ariely 31 that people want to get a good bargain,but they also want to reduce risk（风险）.That is ,they want to 32 The chance of making a 33 .If you pay 14 cents for a piece of chocolate,and then you don’t 34 like it when you eat it,you have lost 14 cents.But when something is free and you don’t like it,you haven’t lost anything.People would 35 not to take a risk over getting a better bargain.
21. A.facing B.buying C.giving D.treating
22. A.posted B.produced C.offered D.told
23. A.if B.as C.for D.but
24. A.getting B.holding C.eating D.making
25. A.dream B.reason C.reply D.surprise
26. A.weight B.size C.price D.quality
27. A working B.thinking C.planning D.looking
28. A.still B.once C.almost D.even
29. A should be B.shouldn’t be C.is D.isn’t
30. A.easy B.old C.normal D.modern
31. A.questioned B.explained C.agreed D.added
32. A.find B.learn C.lower D.take
33. A.decision B.mistake C.promise D.warning
34. A.usually B.gradually C.certainly D.actually
