物体的加速度与所受的合外力成正比,与物体的质量成反比。加速度的方向与合力的方向相同。
The method of psychology must be as exact as that of the physical sciences.
I'm not a brand, I'm a human being.
不要为了别人而活,要为自己而活。
The organism learns not only what to do but also what leads to what.