Question

What is a mass extinction?
a.When a single species is completely knocked out of existence
b.When catastrophic events lead to many deaths of a variety of species
c.When huge numbers of species die out in a short period to time
d.When huge numbers of species die out in a long period of time

Answer 1

c) when huge numbers of species die out in a short period...

Answer 2

when a huge number of species die out in a short amount of time