D. intensity
hope this helps
Answer:
Muscles work in pairs to move a bone.
Explanation:
Skeletal muscles only PULL in one direction. For this reason they always come in pairs. When one muscle in a pair contracts, to bend a joint for example, its counterpart then contracts and pulls in the opposite direction to straighten the joint out again.
Answer:
A. Measuring intensity by one's "effort" (a subjective measure) is an accurate measure of intensity.
Explanation:
I hope this helps!
-Justin
D) twisted ladder. Also known as the double helix, discovered by Watson amd Cric.