Which group of words from the passage best helps the reader understand the meaning of the word extinction?
The Extinction of Dinosaurs
We all know that at one time dinosaurs roamed the surface of Earth. But it has been 65 million years since they died out. They thrived on the
planet for many years, along with a vast number of other organisms and animals. How did the dinosaurs go extinct?
Scientists formed many theories about what caused the death of this entire species. They included climate change, continental shifts, and
volcanoes.
Eventually, one theory began to suggest that the cause of the dinosaurs' extinction was the crash of an asteroid on Earth's surface. It was a huge
asteroid (about 10 kilometers in width) that crashed against Earth. Its crash made a gigantic crater in Mexico. The crash caused total climatic shifts
and changes in the temperature of the atmosphere. The crash also produced a great gas cloud around Earth that resulted in total darkness. It was
this explosion that might have led to the complete extinction of the dinosaurs from the face of Earth.