问题 单项选择题

关于浆细胞白血病的叙述不正确的是()

A.临床上呈现白血病的表现

B.外周血浆细胞增多

C.骨髓浆细胞明显增生

D.尿中可检出凝溶蛋白

E.不可继发于淋巴瘤等疾病

答案

参考答案:E

解析:浆细胞白血病一般可分为原发性浆细胞性白血病(PPCL)及继发于多发性骨髓瘤、淋巴瘤、慢淋、巨球蛋白血症等的继发性浆细胞白血病(SPCL)。血片内可见大量浆细胞,>20%或绝对值≥2×109/L,包括原始和幼稚浆细胞,形态异常。骨髓增生极度活跃或明显活跃。骨髓内各阶段异常浆细胞明显增生,可达10%~92%,包括原浆细胞、幼浆细胞、小型浆细胞和网状细胞样浆细胞。多数患者尿中可查出凝溶蛋白。临床上呈现白血病的临床表现或多发性骨髓瘤的表现。

阅读理解

Why did humans evolve to walk upright? Perhaps because it’s just plain easier. Make that “energetically less costly”, scientifically speaking.

Bipedalism—walking on two feet, is one of the defining characteristics of being humans, and scientists have debated for years how it came about. In the latest attempt to find an explanation, researchers trained five chimps(黑猩猩)to walk on a treadmill(跑步机)while wearing masks that allowed measurement of their oxygen consumption. The chimps were measured both while walking upright and while moving on their legs and knuckles(膝关节).That measurement of the energy needed to move around was compared with similar tests on humans and the results are published in this week’s online edition of “Proceedings of the National Academy of Sciences”.

It turns out that humans walking on two legs use only one-quarter of the energy that chimps use while knucklewalking on four limbs(肢).And the chimps, on average, use as much energy using two legs as they did when they used all four limbs.

However, there were differences among chimps in how much energy they used, and this difference corresponded to their different manner of walking and anatomy(解剖构造).One of the chimps used less energy on two legs, one used about the same and the others used more, said David Raichlen, assistant professor of anthropology at the University of Arizona.

“What we were surprised at was the variation(变异) ”, he said in a telephone interview. Interview. “That was pretty exciting, because when you talk about how evolution works, variation is the bottom line, without variation there is no evolution.”

Walking on two legs freed our arms, opening the door to drive the world, said Raichlen. “We think about the evolution of bipedalism as one of first events that led hominids(原始人)down the path to being humans.”

The research was supported by the National Science Foundation and the L.S.B.Leakey Foundation.

小题1: The underlined word “Bipedalism” in Paragraph 2 probably means____.

A.moving sideways

B.walking upright

C.walking on four legs

D.running fast小题2:We can infer from the passage that____.

A.scientists have no idea on how humans’ walking on two legs came about

B.scientists have had different views on why chimps walk on four legs

C.scientists have had different views on how humans’ walking on two legs vame about

D.scientists have had similar views on how humans’ walking on two legs came about小题3:What is Paragraph 4 mainly about?

A.How chimps saved energy.

B.Why chimps didn't walk on two legs.

C.David Raichlen studied chimps.

D.Different chimps consumed different energy.小题4: According to the passage, humans walk upright in order to____.

A.conserve energy

B.differ from other animals

C.free their brains

D.strengthen their legs

问答题