Answer:
Explanation:
More than 99 percent of all organisms that have ever lived on Earth are extinct. As new species evolve to fit ever changing ecological niches, older species fade away. But the rate of extinction is far from constant. At least a handful of times in the last 500 million years, 75 to more than 90 percent of all species on Earth have disappeared in a geological blink of an eye in catastrophes we call mass extinctions.
Though mass extinctions are deadly events, they open up the planet for new forms of life to emerge. The most studied mass extinction, which marked the boundary between the Cretaceous and Paleogene periods about 66 million years ago, killed off the nonavian dinosaurs and made room for mammals and birds to rapidly diversify and evolve.
C. their credibility and relevance
A) (Sentence 2) The freighter Florentine, 320 miles northeast of the Hawaiian Island of Hilo was lumbering along at about 15 knots when a garbled message came in over the radio.
This is the sentence that has a missing necessary comma. Another comma should have been placed after the word Hilo and before was.
The commas in this sentence enclosed nonessential information.
<span>The freighter Florentine, 320 miles northeast of the Hawaiian Island of Hilo, was lumbering along at about 15 knots when a garbled message came in over the radio.
</span>
Nonessential information means that if the said phrase is deleted from the sentence, then the sentence would still convey the same message.
<span>
The freighter Florentine was lumbering along at about 15 knots when a garbled message came in over the radio.</span>