Ammonoids are good as index fossils because of the following characteristics;
<span>1.
</span>Their abundance and vast distribution across most shallow
marine waters during the periods
<span>2.
</span>They have easily recognizable
features, such as shells and the highly crenulated and complex suture, that are well preserved in rocks
<span>3.
</span>Their rapid
evolution that can assist determine changes and variations in the then environment
False like blood lymph won't flow both to and from the heart
think its the second one,have a nice day
Answer:
B
Explanation:
"Energy is generated in a red dwarf in the same way that it is in the Sun, namely through the fusion of hydrogen into helium. ... So long is the process, in fact, that the lifespan of a red dwarf can be far longer than the expected age of the universe, thought to be about 14 billion years."