英译汉
① in need ____ ②voluntary work ____
③ organize a competition ____ ④suffer from ____
⑤raise one’s spirits ____
This is public place for us to do some reading. Don't talk or laugh loudly in public.
设全集U=R,A=x|2xx-2<1,B=x|y=ln1-x,则右图中阴影部分表示的集合为( )
函数y=2-x+1x-1中自变量x的取值范围是( )