视线的焦点随着速度增加而距离()。
A.变近
B.变远
C.模糊
D.变宽
参考答案:B
It rains so ______ that people can ______ go hiking in the mountains. [ ]
A. hardly, hardly
B. hard, hard
C. hard, hardly
D. hardly, hard
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