已知a＜0，－1＜b＜0，则a，ab，ab2之间的大小关系是（ ）
A．a＞ab＞ab2
B．ab＞ab2＞a
C．ab＞a＞ab2
D． ab＜a＜ab2
答案：B
先根据同号得正的原则判断出ab的符号，再根据不等式的基本性质判断出ab2及a的符号及大小即可．
解：∵a＜0，b＜0，
∴ab＞0，
又∵-1＜b＜0，ab＞0，
∴ab2＜0．
∵-1＜b＜0，
∴0＜b2＜1，
∴ab2＞a，
∴a＜ab2＜ab．
故选B
本题涉及到有理数的乘法及不等式的基本性质，属中学阶段的基础题目．
Many people think that Americans 21 their cars almost more than anything else. When 22__ people are fourteen years old, they want to have their __23_ cars. They don’t ask for a car from their 24__. So many of them work in _25_ time during their last year of high school to buy a car. Learning to 26 _ and getting a driver’s license may be one of the most exciting things in a young person’s life. Some people almost 27 _ go to a doctor when they are ill. But they will __28_ their cars to a garage as soon as they think there is a 29 . On Saturdays or Sundays some people may 30 most of their time washing and repairing their cars.
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