← Back to Test
Problem 4 - Entrance Test
The following passage is a excerpt from a nonfiction book. Read the passage and then choose the best answer to the question that follows.
"The concept of dark matter has been a topic of debate among scientists for decades. Although it has yet to be directly observed, its presence can be inferred by its gravitational effects on visible matter. Many scientists believe that dark matter makes up a large portion of the universe's mass-energy budget."
The author's tone can best be described as