生活在不同区域的两种动物之间如果能够进行交配产生可育后代,可以认为这两种动物是同一个物种。( )
参考答案:对
— How do you find air conditioners made by Haier Group Corporation?
— Of high quality. We ______ their products all these years. [ ]
A. sell
B. have sold
C. have been sold
D. have been selling
简述YJ29滤嘴接装机取出鼓轮及铲刀的清洁保养步骤。