$\text{A.}$ $-\int_0^2 x(x-1)(2-x) \mathrm{d} x$ ．
$\text{B.}$ $\int_0^1 x(x-1)(2-x) \mathrm{d} x-\int_1^2 x(x-1)(2-x) \mathrm{d} x$ ．
$\text{C.}$ $-\int_0^1 x(x-1)(2-x) \mathrm{d} x+\int_1^2 x(x-1)(2-x) \mathrm{d} x$ ．
$\text{D.}$ $\int_0^2 x(x-1)(2-x) \mathrm{d} x$ ．
$\text{E.}$
$\text{F.}$