Answer:
7) The Cretaceous period and it lasted for 80 million years
8) The Cenozoic era for 65 million years
9) 4.5 billion years ago
10) It began 252.2 million years ago
11) It ended 66 million years ago
12) About 190 million years
Explanation:
Hope this helps :)
Answer:
glass like.
Explanation:
Like obsidian, if you break it it will be really sharp.
Since this is a square you can set 3x+20=5x then you can solve for x.
Subtract 3x from both sides:
3x-3x+20=5x-3x
20=2x
Divide both sides by 2
20/2=2x/2
10=x
Hope this helps.
Rust,good conductor of heat and electricity.