Since the sales promotion, all the items _______well.

A．have been sold

B．were sold

C．had sold

D．have been selling

打开空调开关后空调压缩机不工作，造成此现象的原因可能是（）

A.离合器间隙过大

B.蒸发器有轻微泄漏

C.循环回路中制冷剂不足

D.环境温度过低