Bend your elbows and pump your arms to add momentum.Be sure not to strain yourself.

借着弯弯手肘和摆动手臂来增加动力。但别伤到自已。

That would be in the part of your arm that bends – your elbow, that is to say.

那将是你手臂弯曲的部分——也就是说， 你的肘部。

When you see the apple, your brain's motor center activates the appropriate muscles, allowing you to reach out with your arm, grab it with your hand, bend your elbow joint, and bring it to your mouth.

当你看见苹果，大脑的运动部分激活合适的肌肉，使你伸出手臂，用手抓住它，弯曲手肘，把它送到你嘴中。