“秋燥”病名首见于：（）
参考答案：清初喻嘉言《医门法律》
– Do you have any plans for this Sunday?
– Yes, I _______ my grandparents.
A. am visiting B. visited C. have visited
A．a为动滑轮，B端钢缆受到滑轮组的拉力大小约为3G
B．a为动滑轮，B端钢缆受到滑轮组的拉力大小约为G
C．a、c为动滑轮，B端钢缆受到滑轮组的拉力大小约为3G
D．a、c为动滑轮，B端钢缆受到滑轮组的拉力大小约为G
G
G