Summarize the whole process step by step how your muscles enable you to do a
sit-up.

Start by lying on your back. Bend your knees at a 90-degree angle, with your feet flat on the floor. Put your fingertips on the back of your ears. Your elbows should be bent and pointing out at your sides. Lift your torso up as close to your thighs as possible. Do this with a smooth, steady motion, keeping your feet flat on the floor. When you’re done lifting your torso, your lower back should be off the floor. Lower your torso down to the floor so you’re back in the starting position.

answer:

the world will never kno

explanation:

answer:

it could come from a variety of sources.

explanation:

..although it was most likely developed through zoonotic transmission, where an infectious disease which usually afflicts when animals jump to humans.