问题
选择题
已知f(x)=
|
答案
因为在每段定义域对应的解析式上都有可能使得f(x)=3成立,所以将原不等式转化为:
或x+1=3 x≤-1
或x2=3 -1<x<2
,从而得x=2x=3 x≥2
.故选D.3
已知f(x)=
|
因为在每段定义域对应的解析式上都有可能使得f(x)=3成立,所以将原不等式转化为:
或x+1=3 x≤-1
或x2=3 -1<x<2
,从而得x=2x=3 x≥2
.故选D.3
完形填空。 | ||||
Everyone 1 to live in a clean and comfortable environment. If the environment is 2 , it will make us not 3 well. Sometimes we may be terribly ill. At that time we don't want to 4 , we have to stay in bed and rest at 5 . So the environment is very important 6 us. It is germ that makes us ill. There are germs everywhere. They are very small and we can't 7 them with our own eyes. To keep us 8 , we should try our best 9 our environment become cleaner and tidier. This needs us to act 10 . | ||||
|