Questions 7-10 refer to the following passage.

The primary purpose of the passage is to

a. Refute a well-established theory

b. Describe a newly discovered natural phenomenon and compare it to another

c. Explain how the study of a certain natural phenomenon has changed over time

d. Evaluate opposing theories

e. Reconsider a natural phenomenon in light of new discoveries

Transcribed Image Text:

"Hydrothermal vent" is the term that scientists use to describe a crack in a planet's surface from which geothermally heated water emerges. Line Because these vents are common in places (5) that are volcanically active, they are plentiful on Earth. While the most famous hydrothermal vent is probably the geyser at Yellowstone National Park in the United States, there are several dif- ferent types of vents, existing both on land and (10) underwater. Black Smokers, for instance, are a common type of submarine vent. The National Oceanic and Atmospheric Administration first discovered these in the vicinity of the Galapa- gos Islands in 1977. Underwater vents such as (15) these form when water that has been heated by magma beneath the earth's crust exits through cracks in the ocean floor. Scientists are inter- ested in these vents primarily for their ability to host biologically dense communities in areas (20) that are otherwise hostile to life. Studies show that Chemosynthetic archaea, a life form similar to bacteria, allows these areas to support such diverse organisms as clams and shrimp. Black Smokers are also visually striking. Minerals in