In this note, we always let $\Omega\subset\mathbf R^n$ be a bounded domain, and assume that $$a_ij,b_i,d_i,c\in L^p(\Omega),$$$$\forall 1\leq i,j\leq n,x\in\Omega,a_{ij}(x)=a_{ji}(x).$$ Let $L$ be defined as following:$$Lu=-\partial_i(a_{ij}\partial_ju+d_iu)+b_i\par ...