1.
action and reaction are equal and opposite.
作用力与反作用力大小相等，方向相反。
2.
The condition of equilibrium of the member requires that the pair of forces coming from the joints must be equal and opposite.
元件的平衡条件要求来自连接点的一对力必须大小相等，方向相反。
3.
To every action there is always opposed an equal reaction; or, the mutual actions of two bodies upon each other are always equal, and directed to contrary parts.
两个物体的相互作用力总是大小相等，方向相反，同时出现或消失且作用于同一直线上。
4.
Action and reaction are opposite and equal.
作用力与反作用力大小相等、方向相反。
5.
The forces between interacting bodies are equal and opposite.
相互作用的物体之间的力大小相等、方向相反。
6.
For every action there is an equal and opposite reaction.
每一个作用力都有一个大小相等、方向相反的反作用力。
7.
The third law of motion tells us that the two forces which constitute such a pair are equal in magnitude and opposite in direction.
运动第三定律告诉我们，像这样成对的两个力大小相等方向相反。
8.
(mechanics) the equal and opposite force that is produced when any force is applied to a body.
（力学）大小相等方向相反，当有任何的力作用于一个物体的力。
9.
The reactions (forces) on each sphere were equal and opposite and directed along the diameter through the point of contact.
每个球上的反作用（力）大小相等方向相反，其作用方向沿着通过接触点的直径。
10.
His third law says that for every action, there is an equal and opposite reaction.
他的第三定律说明，每种作用力都有大小相等、向相反的反作用力。
11.
If a force acts on a Body then an equal and opposite force must act upon another Body.
如果一个力作用于某一物体，那么，必定有一个大小相等、方向相反的力作用于另一物体。
12.
For every force that acts on one body there is a second force equal in magnitude but opposite in direction that acts upon another body.
对于作用在一物体上的任一力来说，总存在着大小相等、方向相反的第二个力作用在另一物体上。
13.
An equal and opposite force exerted by a body against a force acting upon it.
反作用力物体对于加在其上的力作出的大小相同，方向相反的力量
14.
For conservation of momentum, the atom must recoil with a momentum of this magnitude in the opposite direction.
因为动量守恒，原子必然以这样大小的动量向相反方向反冲。
15.
The air pressure that action carries on the head in tent is 0, the pressure of fluctuation double air because of tent is equal and way is opposite and quits.
作用在帐篷顶的大气压力是0，因为帐篷的上下两面的大气压力相等且方向相反而抵消。
16.
In a contrary manner or direction.
反方向地,相反地,对立地
17.
The plane is flying a contrary direction.
飞机向相反的方向飞去。
18.
They were walking in opposite ways.
他们向相反的方向走着。