试题与答案

二卵双胎受下列各项影响,其中哪项不正确() A.种族 B.孕妇年龄 C.分娩次数 D

题型:单项选择题 A1型题

题目:

二卵双胎受下列各项影响,其中哪项不正确()

A.种族

B.孕妇年龄

C.分娩次数

D.父亲年龄

E.遗传

答案:

参考答案:D

解析:本题考点是双胎妊娠发生的原因。虽然母亲的年龄与二卵双胎有关,但父亲年龄似乎对二卵双胎的发生率没有影响。有家族史、分娩次数多、年龄大者易发生,促排卵药物的应用以及种族均可影响多胎妊娠的发生率。

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题型:单项选择题

Under pressure from animal welfare groups, two national science teachers associations have adopted guidelines that ban classroom experiments harming animals. The National Association of Biology Teachers and the National Science Teachers Association hope to end animal abuse in elementary and secondary schools and, in turn, discourage students from mishandling animals in home experiments and science fair projects.

Animal welfare groups are apparently most concerned with high school students experimenting with animals in extracurricular projects. Barbara Orlans, President of the Scientists’ Center for Animal Welfare, said that students have been performing surgery at random, testing known poisonous substances, and running other pathology experiments on animals without even knowing normal physiology.At one science fair, a student cut off the leg and tail of a lizard to demonstrate that only the tail can regenerate, she said. In another case, a student bound sparrows, starved them and observed their behavior.

"The amount of abuse has been quite horrifying," Orlans said.Administrators of major science fairs are short-tempered over the teachers’ policy change and the impression it has created. "The teachers were sold a bill of goods by Barbara Ortans," said Thurman Grafton, who heads the rules committee for the International Science and Engineering Fair. "Backyard tabletop surgery is just nonsense. The new policies throw cold water on students’ inquisitiveness," he said.

Grafton said he wouldn’t deny that there hasn’t been animal abuse among projects at the international fair, but he added that judges reject contestants who have unnecessarily injured animals. The judges have a hard time monitoring local and regional fairs that may or may not choose to comply with the international fair’s rules that stress proper care of animals, Grafton said.

He said that several years ago, the Westinghouse Science Talent Search banned harmful experiments to animals when sponsors threatened to cancel their support after animal welfare groups lobbied for change.

The teachers adopted the new policies also to fend off proposed legislation--in states including Missouri and New York--that would restrict or prohibit experiments on animals.

Officials of the two teachers organizations say that they don’t know how many animals have been abused in the classroom. On the one hand, many biology teachers are not trained in the proper care of animals, said Wayne Moyer, executive director of the biology teachers’ association. On the other, the use of animals in experiments has dropped in recent years because of school budget cuts. The association may set up seminars to teach better animal care to its members. (414 words)

Notes: pathology 病理学。lizard 蜥蜴。tabletop 桌面。short-tempered 脾气急躁的。lobby for 游说支持。fend off 躲开。

Thurman Grafton suggests that()

A. animal abuse is horrible and should be terminated

B. the teachers have been compelled to do all animal experiments

C. prohibition of experiments on animals will discourage students from being curious

D. the international science and Engineering Fair will cease to operate because of the new policies

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