A:氧气
B:二氧化碳
C:水蒸气
D:氮气
________ we deal with our problems, we can easily become unhappy.
若x1,x2(x1<x2)是方程(x-a)(x-b)=1(a<b)的两个根,则实数x1,x2,a,b的大小关系为( )