Question

Which of the following most likely happens when astronauts go to space?

1. Their heart rate speeds up because the blood vessels have less blood to circulate.

2. Their heart rate speeds up because the blood vessels have more blood to circulate.

3. The blood vessels in their neck caves in because the heart pumps less blood per beat.

4. The blood vessels in their neck bulges out because the heart pumps more blood per beat.

Answer 1

Answer:

I think 2nd

Explanation:

no confirm.......