Let the function f (x) = ex+2x; Then f(x) is the increasing function at (0, +∞),

So f (a) = e a+2a, and f (b) = EB+2B;

From A, we can know that: f (a) = f (b)+b; That is f (a)-f (b) = b >; 0;

So f(a)>f(b); So choose a.

Let g (x) = e x-2x,? g？ (x)= e x-2 in x & gt； The sign of 0 is uncertain, so D and C can't judge right or wrong.