46. According to the passage, the layers in varves are primarily formed by
(A) fossilized bacteria
(B) pieces of ancient dropstones
(C) a combination of ancient and recent sediments
(D) annual cycles of sediment transport and deposition

42. According to the passage, the fossil record of the Proterozoic con is (A) highly regarded because it preserves the remains of many kinds of organisms (B) less informative than the fossil record of more recent periods (C) very difficult to interpret due to damage from bacteria (D) more useful to researchers than other aspects of the rock record

43.The word “scarce” in line 4 is closest in meaning to (A) ancient (B) tiny (C) available (D) rare

44. It can be inferred from the passage that the principle of uniformitarianism indicates that (A) similar conditions produce similar rock formations (B) rock layers in a given region remain undisturbed over time (C) different kinds of sedimentary rocks may (D) each continent has its own distinctive pattern of sediment layers

45. The word “resemble” in line 14 is closest in meaning to (A) result from (B) penetrate (C) look like (D) replace have similar origins

47. The phrase “the other” in line 17 refers to another (A) annual cycle (B) glacial lake (C) layer of sediment (D) season

48. According to the passage, the presence of dropstones indicates that (A) the glacial environment has been unusually server (B) the fine-grained sediment has built up very slowly (C) there has been a global ice age (D) coarse rock material has been carried great distances

49. Why does the author mention Canada, North America, Africa, India, and Europe in lines 23-24? (A) To demonstrate the global spread of dropstones (B) To explain the principles of varve formation (C) To provide evidence for the theory that there was a global ice age in the early Proterozoic eon (D) To illustrate the varied climatic changes of the Proterozoic con in different parts of the globe

50. Which of the following terms is defined in the passage? (A) fossil record (line 3) (B) laminae (line 13) (C) varves (line14) (D) glacial episodes (line 29)

1. Which of the following aspects of glass fiber does the passage mainly discuss? (A) The major developments in its production (B) Its relationship with pottery making (C) Important inventors in its long history (D) The variety of its uses in modern industry

2. The word "coarse" in line 1 is closest in meaning to (A) decorative (B) natural (C) crude (D) weak