题目

You will have a lot of reading to do in this grade this year. You can do more of it in less time if you learn to read rapidly. Perhaps you have been told about some habits which keep a person from reading fast and have been strongly asked to break those which you might have.   Do you still have any of these bad habits? Check yourself by answering “yes” or “no” to these questions. （1）Do you move your lips(嘴唇) when reading silently?    （2）Do you point to words with your finger as you read? （3）Do you move your head from side to side as you read?   ( 4 )Do you已知y＝f(x)是定义在R上的奇函数，当x≤0时，f(x)＝2x＋x2.（1）求x>0时，f(x)的解析式；（2）若关于x的方程f(x)＝2a2＋a有三个不同的解，求a的取值范围．