The quality of this transition is best visualized by a straight line drawn between two circles: the line's only point of contact with each circle is tangential.

用最明显的图形来描述这个过渡的特性就是：当在两个圆之间绘制一条直线，直线与每个圆只有一个交点时，那么这条线就是两个圆的切线。

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In small tooth difference of inner meshed transmission, there were a few pairs of tooth faces which were apart from each other for a small gap beside the contact point generated by two meshed teeth.

在少齿差内啮合传动中，存在多对接近啮合的小间隙齿面于理论啮合点左右，轮齿受力产生的微小变形使得某些对齿面相互接触进入啮合状态。

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The two elements of a lower pair have theoretical surface contact with one another, while the two elements of a higher pair have theoretical point or line contact (if we disregard deflections).

这两个因素中的低副是两个理论表面之间的接触，而这两个因素中的高副是理论的点或线接触(如果我们忽视了挠度)。

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"Gary will go another two weeks without any contact but from that point he'll join in with the group, " added Coyle.

BBC: Gary Cahill could return for Bolton in four weeks' time

If Microsoft is content to let us do everything with a single point of contact at a time, or at best two points (in the case of pinch and rotate) what good is 10-finger pressure-sensitive multitouch when it comes to navigating an OS or actually getting things done?

ENGADGET: Stantum multitouch Slate PC prototype hands-on Hands-on

To create the point-contact transistor, Shockley's team modified the cat's whisker by placing two fine metal wires close together on the surface of a germanium crystal, turning it from a diode into a triode.

ECONOMIST: The middle age of the transistor