在密闭容器中一定量混合气体发生如下反应:xA(g) + yB(g) zC(g) 平衡时测得A的浓度为0.50 mol/L,保持温度不变,将容器的容积扩大到原来的两倍,再达平衡时,测得A的浓度降低为0.30mol/L。下列有关判断正确的是 ( ) A.x + y < z B.平衡向正反应方向移动 C.B的转化率降低 D.C的体积分数增大— Why is your bedroom so dirty?— Sorry, Mum. It ___________. I felt very tired after playing soccer.A. isn’t cleaned B. didn’t cleanC. doesn’t clean D. wasn’t cleaned