Question:
A joint produces movement when its angle decreases.
Answer:
It is B, rotation because it allows the joint to rotate.
Proteins or polypeptides. (They are interchangeable)
Yes
(explanation: i really just needed to answer a question, so thank you)
Bipolar. Mental illness where you either have a lot of energy or none at all.
Although you are only presenting one aspect of a mental illness that could be related to more than bipolar.