They have a spine
hope it helps
Nearly 99% of the mass of your human body consists of just 6 chemical elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Another 5 elements make up most of the last percentage point: potassium, sulfur, sodium, chlorine, and magnesium.
<span>~Hello there!
Your question: Sam came home from school with a cold caused by a virus and his sister, Ana, caught it from him. Sam got well and went back to school. A few days before Ana got well, Sam came down with a cold again. Their mother said that Ana had given the cold back to Sam. How likely is it that their mother is correct, and what does it mean for Ana's chances of
getting sick again?
Your answer: Acquired immunity, he must have picked picked up a different disease virus so Ana can get sick again.
The answer is option A.
Hope this helps~
</span>
You do not need to plan. that was a false statement
Wave energy remains constant as water depth changes.