Why is it necessary for vertebrae to be hollow in the center?

According to the big bang theory, after the "bang," the universe remained dark until about  300,000 yearsone billion yearsthree minutesthree billion years  later, when neutral atoms began to form.

Which organelle breaks down sugar molecules that supply energy to the cell ?

Pls ! in your opinion, what are the limiting factors that might affect the growth or diversity of our ecosystem? respond to this question in claim, evidence, reasoning format. 1. make your claim (i are the limiting factors that might affect the growth or diversity of our 2. follow the claim with 3 pieces of evidence. evidence may be taken from the reading, the videos, previous lessons, or googled answers. site sources, too. 3. use reasoning to explain why you chose your evidence.