41. The word "milestone" in line 20 is closest in meaning to
(A) significant development
(B) initial step
(C) universal concept
(D) obstruction to progress

37.The phrase "shied away from" in line 8 is closest in meaning to (A) approached (B) avoided (C) respected (D) allowed

38.What does the author mean when stating in line 14 that "The experiment called for familiarizing the animal with the mirror? (A) The experiment required the use of a chimpanzee that had not participated in previous mirror tests. (B) Gallup had to allow the chimpanzee to become accustomed to the mirror before he began the experiment. (C) Gallup had to teach the chimpanzee to recognize its reflection in the mirror. (D) The chimpanzee had to first watch the experiment being conducted with another chimpanzee.

39.The word "it" in line 16 refers to (A) red spot (B) animal (C) reflection (D) another individual

40. The chimpanzee in Gallup's first experiment responded to the mirror test by touching (A) its own forehead (B) the researcher's forehead (C) the red spot on the mirror (D)the red spot on another chimpanzee

42. What does the passage mainly discuss? (A)The causes of the extinction of the discuss? (B)The variety of species found in tropical rain forests. (C) The impact of human activities on Earth's ecosystems (D) The time required for species to adapt to new environments

43. The word "critical" in line 1 is closest in meaning to (A) negative (B) essential (C)interesting (D) complicated

44. The word "jolting" in line 5 is closest in meaning to (A) predicted (B) shocking (C)unknown (D) illuminating

45. The author mentions the reduction of the variety of species on Earth in lines 11 - 12 to suggest that (A) new habitats can be created for species (B)humans are often made ill by polluted water (C) some species have been made extinct by human activity (D)) an understanding of evolution can prevent certain species from disappearing

46. The author mentions all of the following as examples of the effect of humans oil the world's ecosystems EXCEPT (A) destruction of the tropical rain forests (B) habitat destruction in wetlands (C)damage to marine ecosystems (D)the introduction of new varieties of plant species

47.The author mentions the extinction of the dinosaurs in the second paragraph to emphasize that (A)the cause of the dinosaurs extinction is unknown (B)Earth's climate has changed significantly since the dinosaurs' extinction, (C)not all mass extinctions have been caused by human activity (D) actions by humans could not stop the irreversible process of a species' extinction