Theextinctflying reptiles called pterosaurs were thesecondgroup of animals (after insects) toevolveflight. Most pterosaurs were about the size of modern seagulls. A few were as small as sparrows, but some of the laterspecieswere the largest flying animals that have ever lived. In 1817 Theodore Von Soemmerring published the first description of a pterosaurfossil, and thinking that it was that of an unusual batspecies, he drew hisreconstructionwith a very batlike posture and wing. His earlyreconstructionof a pterosaur has haunted the public andscientificperceptionof pterosaurs ever since. Soemmerring’sreconstructionis understandablegiventhat he was the first to try todescribea pterosaur, thatfew naturalists of the time accepted the idea ofmajorgroups ofextinctanimals, and that both pterosaurs’ and bats’ wingsconsistof amembranesupported by enormouslyelongatedfinger bones. Soemmerring showed his pterosaur with the laterally directed legs and reoriented feet of bats and with the wingmembranestretching from the arm and fingeralongthe sides of the body and legs all the way to the ankle. Thereconstructionalso included amembranestretching between the legs,similarto that in bats. Eventhough other scientists developed less batlike descriptions of pterosaurs in the late 1800s, thepopularliterature, andevensomescientificliterature, continued todescribepterosaurs as batlike into the 1980s.

Batsperchby hanging upside down from tree limbs and roofs of caves. Though many are surprisinglyagileclimbers, bats are generallyawkwardwhen crawling onlevelsurfaces. Did pterosaurs also hang upside down andavoidlandingon the ground? Until recently, some paleontologists thought they did, but most scientists now agree that pterosaurs got around on the ground reasonably well. What is still uncertain is whether pterosaurs walked on all fours or just on their hindlegs. Pterosaurs’ ancestors were bipedal (two-footed) and used their tails tobalancetheir forward-tilted trunks and heads. Early pterosaurs also had long tails and probably could have run on their hindlegs, certainlyhandyfor an animal with wings for forelimbs. These early pterosaurs, however, could have used their forelimbs for walking because their arm and hand bones were onlyslightlyenlarged—most of the wing was supported by thegiganticfourth finger.

Later pterosaurs are more enigmatic: their arms and especially their handsseemtoo long to be used comfortably for walking, but their tails were too short to counterbalance their bodies if they walked just on their hindlegs. Birds also have short,stubbytail skeletons, but theymanageto walk quite well on their hindlegs. Birdsmanagethis by angling the thighsforwardto get their feet under the body’s center ofgravity. They hold their thighs at this unstableanglewithextensivehip and thigh muscles. Some researchers have suggested that pterosaurs’ hipbones were too small toanchorextensivethigh-positioning muscles, but others have responded that pterosaurs’ leg and foot bones are so strikingly birdlike that pterosaurs must surely have walked like birds. Recently, however, some pterosaur experts have concluded that a number offossiltrackways—trails of preserved footprints—were made by pterydactyloid pterosaurs, and these animals clearly walked on all four limbs. Perhaps some early pterosaurs walked on their hindlegs, but according tocurrentevidence, mostspeciesprobably walked on all fours. In any case, large pterosaurs, with eight- or ten-meter wingspans and weighing as much as an adult human, do notseemlikely candidates for a batlikeexistenceconfined to clambering about in trees and hanging upside down from branches.

Pterosaurs also possessed someobviousadaptations for powered flight. They had large sternums (breastbones) for attaching powerful flight muscles, well-developed shoulder bones to carry the body’s weight in flight, and air-filled bones to lighten theskeleton. Someevenhad a furcula (a fused breastbone also found in birds), perhaps to flex like aspringand helpraisethe wings during the upstroke. Howcompetentwere they at flying? Theoriginalbatlike reconstructions,alongwith theirclassificationas reptiles, suggested to many earlier biologists that pterosaurs were only gliders. Biologists now, however, generally agree that pterosaurs werecapableof powered, flapping flight. Indeed, the shoulderjointis clearlyspecializedfor the down-and-forward, up-and-back movement of normal flapping.

Questions:
question_stem: In the discussion of Soemmerring in paragraph 1, why does the author mention that “few naturalists of the time accepted the idea of major groups of extinct animals”?
choices: tag: A
text: To support the position that Soemmerring was the first to recognize the scientific significance of pterosaur fossils

tag: B
text: To suggest that Soemmerring’s reconstruction of the pterosaur went against a commonly accepted position of naturalists at that time

tag: C
text: To help explain why it was reasonable for Soemmerring to think that pterosaurs were related to today’s bats

tag: D
text: To indicate how little was known about pterosaurs before Soemmerring published his reconstruction
answer_key: C
explanation: 题干提问“作者为何提及很少有博物学家接受翼龙是灭绝动物的主要类群的想法”。
定位第1段高亮句，所在句是由 and 构成的并列句，并列三个 that 引导的从句作原因解释逐句。
该句理解为“苏默梅林的重现描述是可以理解的，因为他是第一个尝试描述翼龙的人，也因为当时很少有博物学家接受翼龙是灭绝动物的主要类群的想法，还因为翼龙和蝙蝠的翅膀都有一层由巨长指骨支撑的薄膜”。
即并列的第2个 that 所在句作为修辞句，是为了解释说明 Soemmerring’s reconstruction is understandable，再结合前文 Soemmerring 对 pterosaurs 的重现描述为 batlike。
故选 C。

question_stem: According to paragraph 1, Soemmerring believed that pterosaurs had all of the following features EXCEPT
choices: tag: A
text: wings that were attached to the sides of the body

tag: B
text: wings without bones

tag: C
text: legs that were oriented laterally

tag: D
text: a membrane between the legs
answer_key: B
explanation: 题干提问“苏默梅林认为翼龙不具备以下哪个特点”，建议先看完四个选项，再逐一对应文本。
定位第1题所在句，both pterosaurs’ and bats’ wings consist of a membrane supported by enormously elongated finger bones，即翼龙翅膀有长长的指骨支撑，与选项 B 的 wings without bones 明显相反；
后一句中 the laterally directed legs and reoriented feet of bats 对应选项 C；
with the wing membrane stretching from the arm and finger along the sides of the body and legs all the way to the ankle 对应选项 A 和 D。
故选 B。

question_stem: The word “awkward”in the passage is closest in meaning to
choices: tag: A
text: careful

tag: B
text: clumsy

tag: C
text: slow

tag: D
text: helpless
answer_key: B
explanation: awkward adj.“笨拙的”，与 clumsy 同义。
故选 B。

question_stem: In paragraph 2, what evidence suggests that early pterosaurs walked on their hind legs only?
choices: tag: A
text: The arm and hand bones on early pterosaurs were enlarged.

tag: B
text: The tails of pterosaurs may have been long enough to use for balance.

tag: C
text: The trunks and heads of early pterosaurs may have been tilted forward.

tag: D
text: The wings of early pterosaurs were largely supported by a single finger.
answer_key: B
explanation: 题干提问“什么证据能表明早期翼龙仅用后脚行走”。
由 hind legs only 定位第2段倒数2-3句 Pterosaurs’ ancestors were bipedal (two-footed) and used their tails to balance their forward-tilted trunks and heads. Early pterosaurs also had long tails and probably could have run on their hindlegs, certainly handy for an animal with wings for forelimbs. 翼龙的祖先是两足动物，并用尾巴来平衡前倾的躯干和头部。早期的翼龙也有长长的尾巴，可能用后腿奔跑，这对于前肢带翅膀的动物来说肯定很方便。
即翼龙的长尾可用来平衡躯干和头部，就可用后腿行走，对应选项 B。
故选 B。

question_stem: The word “slightly”in the passage is closest in meaning to
choices: tag: A
text: a little

tag: B
text: in part

tag: C
text: gradually

tag: D
text: occasionally
answer_key: A
explanation: slightly adv.“轻微地”，与 a little 同义。
故选 A。

question_stem: The word “strikingly”in the passage is closest in meaning to
choices: tag: A
text: perfectly

tag: B
text: suspiciously

tag: C
text: remarkably

tag: D
text: elegantly
answer_key: C
explanation: strikingly adv.“显著地，突出地，引人注目地”，与 remarkably 同义。
故选 C。

question_stem: What evidence is presented in paragraph 3 that at least some pterosaurs walked on all four of their limbs?
choices: tag: A
text: The position of their feet relative to the body’s center of gravity in some pterosaurs

tag: B
text: The considerable wingspan and weight of some pterosaurs

tag: C
text: Fossil trackways left by some pterosaurs

tag: D
text: The shape of the leg bones and feet bones in some pterosaurs
answer_key: C
explanation: 题干提问“至少有些翼龙是四脚行走的证据是什么”。
由 all four of their limbs 定位第3段词汇题 strikingly 后一句 Recently, however, some pterosaur experts have concluded that a number of fossil trackways—trails of preserved footprints—were made by pterydactyloid pterosaurs, and these animals clearly walked on all four limbs. 一些翼龙专家总结到翼龙类翼龙留下了许多化石轨迹，所以这些动物显然是用四肢行走的。
即 fossil trackways trials 可作为证据说明一些翼龙 walked on all four limbs，对应选项 C。
故选 C。