【正文】 on years old, a time shortly after the Cambrian explosion。 they were found on a mountainside in British Columbia in a deposit known as the Burgess Shale. The Burgess Shale fossils are extraordinarily important because among them are remains of softbodied creatures, many of them lacking shells and other hard parts that fossilize easily. Consequently, their preservation is little short of miraculous (as are the delicate methods used to reconstruct threedimensional structure from these flattened fossils), and they are one of the few known repositories of early softbodied animals. Not all of the Burgess animals had eyes. However, some did. (Gross features location, size, and hemispheric shape are responsible for the designation of some structures as eyes). The reconstructed eyes of these Burgess animals look superficially like eyes of some living crustaceans, particularly those of shrimp and crabs whose eyes are mounted on stalks that improve the range of vision by raising the eyes above the surface of the head. The eyes of some Burgess anisms sat on stalks。 at least one of the lateral pairs had stalks that could have been movable. And some trilobitelike animals in the Burgess Shale had faceted eyes much like those of later fossil trilobites. Although the presence of eyes on some of the Burgess animals indicates that eyes have been around for a very long time, it is unlikely that these were the first eyes。 they were found on a mountainside in British Columbia in a deposit known as the Burgess Shale. The Burgess Shale fossils are extraordinarily important because among them are remains of softbodied creatures, many of them lacking shells and other hard parts that fossilize easily. Consequently, their preservation is little short of miraculous (as are the delicate methods used to reconstruct threedimensional structure from these flattened fossils), and they are one of the few known repositories of early softbodied animals. 7. The phrase little short of miraculous is closest in meaning ? To very highly valued ? Amazing because almost impossible ? Causing controversy ? Almost but not quite plete 8. According to paragraph 4, all of the following are true of the Burgess Shale EXCEPT: ? Its fossils were in a flattened condition when discovered. ? Its fossils provide direct evidence about the origin of eyes. ? It contains fossils of both Precambrian and Cambrian animals. ? It contains fossilized remains of softbodied anisms. Paragraph 5: Not all of the Burgess animals had eyes. However, some did. (Gross features location, size, and hemispheric shape are responsible for the designation of some structures as eyes). The reconstructed eyes of these Burgess animals look superficially like eyes of some living crustaceans, particularly those of shrimp and crabs whose eyes are mounted on stalks that improve the range of vision by raising the eyes above the surface of the head. The eyes of some Burgess anisms sat on stalks。 at least one of the lateral pairs had stalks that could have been movable. And some trilobitelike animals in the Burgess Shale had faceted eyes much like those of later fossil trilobites. 9. The word designation in the passage is closest in meaning to ? Evolution ? Identification ? Reconstruction ? Confusion 10. The word lateral in the passage indicates a location at the ? Front ? Back ? Top ? Side 11. Why does the author point out that The eyes of some Burgess anisms sat on stalks? ? To suggest that some Burgess anisms had a greater range of vision than do living shrimp and crabs ? To explain why it is thought that one of the lateral pairs of eyes in Opabinia may have been movable ? To explain why the eyes of some Burgess animals were not recognizable as such before they were reconstructed ? To support the statement that the reconstructed eyes of Burgess animals look superficially like the eyes of some living crustaceans Paragraph 6: Although the presence of eyes on some of the Burgess animals indicates that eyes have been around for a very long time, it is unlikely that these were the first eyes。s atmosphere, we must go back to the earliest days of the solar system, before the plas themselves were formed from a disk of rocky material spinning around the young Sun. This material gradually coalesced into lumps called plaesimals as gravity and chance smashed smaller pieces together, a chaotic and violent process that became more so as plaesimals grew in size and gravitational pull. Within each orbit, collisions between plaesimals generated immense heat and energy. How violent these processes were is suggested by the odd tilt and spin of many of the plas, which indicate that each of the plas was, like a billiard ball, struck at some stage by another large body of some kind. Visual evidence of these processes can be seen by looking at the Moon. Because the Moon has no atmosphere, its surface is not subject to erosion, so it retains the marks of its early history. Its face is deeply scarred by millions of meteoric impacts, as you can see on a clear night with a pair of binoculars. The early Earth did not have much of an atmosphere. Before it grew to full size, its gravitational pull was insufficient to prevent gases from drifting off into space, while the solar wind (the great stream of atomic particles emitted from the Sun) had already driven away much of the gaseous material from the inner orbits of the solar system. So we must imagine the early Earth as a mixture of rocky materials, metals, and trapped gases, subject to constant bombardment by smaller plaesimals and without much of an atmosphere. As it began to reach full size, Earth heated up, partly because of collisions with other plaesimals and partly because of increasing internal pressures as it grew in size. In addition, the