常开触点是指当接触器线圈通电时，接触器的触点处于断开状态。( )
参考答案：错
I have ________ French. What about you?
A．many difficulties to learn
B．a few troubles in learning
C．quite a little difficulty to learn
D．a great deal of trouble learning
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