A) fires, earthquakes, and tsunamis killed most of the dinosaurs.
B) lowered temperatures decimated many species.
C) the impact of the asteroid caused volcanoes to erupt.
D) there is no consensus on what caused the KT extinction.46 .As used in line 44 and line 73, the phrases “final nail in the coffin,” and “nail in that
coffin” in both passages refer to
A) a profound deduction.
B) a deadly result.
C) a gruesome metaphor.
D) a terminating event.
47 .The author’s reference to the “high-precision radiometric dating techniques” in lines 68-
69 primarily serves to
A) propose a new theory.
B) validate the study’s data.
C) prove the conclusion right.
D) counter the assumption.
48 .As used in line 97, “preclude” most nearly means
A) cause.
B) limit.
C) bar.
D) tap.49 .The author of Passage 2 mentions tektites (line 83) primarily in order to
A) explore another cause for the KT extinction.
B) diminish the role of the asteroid in the demise of the dinosaurs.
C) substantiate that the volcanoes caused the most damage.
D) contrast with volcanic ash in order to support the new theory.50 .Which choice provides the best evidence for the answer to the previous question?
A) Lines 19-23 (“Scientists have previously...years”)
B) Lines 61-65 (“Earth’s climate may...said”)
C) Lines 92-97 (“The previous data...relationship”)
D) Lines 106-108 (“He says ecosystems...struck”)51 .The passages differ in that Passage 1