Answer:
b. the Paleozoic Era
Explanation:
The first vertebrates to appear are primitive fish in the Cambrian Period, but bony fishes with actual bony vertebratae didn't appear for another 100 million years. The Cambrian Period is the first of three periods in the Paleozoic Era. The Cambrian explosion was an event when practically all major animal phyla started appearing in the fossil record.
Answer:
Substance 1 because it became a liquid faster
Explanation:
Answer: gold ,oxygen magnesium
Explanation:
we cannot conclude air because it is mixture of gases , blood is also mixture of plasma , thrombocyte ; co2 is a compound ,
B is correct because most of the cells look the same so it's B
Answer:
0.5 , 54.5
Explanation:
for acceleration we should derivate the equation 2 times
x=3t³+t²/4
v=9t²+t/2
a=18t+1/2
a(0)=0.5
a(3)=54.5