在过去的世纪中,古生物学家用化石标本间的细微差别把三角恐龙分为16类。但是这种划分并不正确,因为用来区分的样本中,11类的标本都是来自生产在同一地区同一时代的动物。下面哪一项,如果正确,能正确地得出以上结论?
A.并不是每一种生活在指定地区的动物都作为化石被保存下来
B.三角恐龙的每个真正种类中,至少会有一个个体被发现作为化石标本。
C.没有一个地理区域在同一时代会有超过3种相似的种类居住。
D.许多种类里的个体之间显示了很大的变异。
【B9】
A.musicians
B.audience
C.judges
D.artists
What means of communication is used by most people?
A.Facial expressions.
B.Body movements.
C.Speech.
D.Body movement and speech.
甲、乙、丙、丁4人分别掌握英、法、德、日四种语言中的两种,其中有3人会说英语,但没有一种语言是4人都会的,并且知道:
(1)没有人既会日语又会法语;
(2)甲会日语,而乙不会,但他们可以用另一种语言交谈;
(3)丙不会德语,甲和丁交谈时,需要丙为他们做翻译;
(4)乙、丙、丁不会同一种语言。
你能说出4个人分别会哪两种语言吗?
A.甲会英语和日语,乙会英语和德语,丙会英语和法语,丁会法语和德语。
B.甲会英语和日语,乙会英语和法语,丙会英语和德语,丁会法语和德语。
C.甲会英语和德语,乙会英语和日语,丙会英语和法语,丁会法语和德语。
D.甲会英语和德语,乙会英语和法语,丙会法语和德语,丁会英语和日语。
SpeakerA: Mind if I call you Albert? Speaker B:__
A.Yes, just call me A1
B.Yes, you may do that
C.Of course not. But just a plain "Al" will do
D.OK. Everyone does
The United States has historically higher rates of marriage than those of other industrialized countries. The current annual marriage【B1】in the United States—about 9 new marriages for every 1,000 people—is substantially higher than it is in other industrialized countries. However, marriage is【B2】as widespread as it was several decades ago. The proportion of American adults who are married【B3】from 72 percent in 1970 to 60 percent in 2002. This does not mean that large numbers of people will remain unmarried【B4】their lives. Throughout the 20th century, about 90 percent of Americans married at some point in their lives. Experts【B5】that about the same proportion of today's young adults will eventually marry.
The timing of marriage has varied【B6】over the past century. In 1995 the average age of women in the United States at the time of their first marriage was 25. The average age of men was about 27. Men and women in the United States marry for the first time at an average of five years later than people did in the 1950s.【B7】, young adults of the 1950s married younger than did any previous【B8】in U.S. history. Today's later age of marriage is in line with the age of marriage between 1890 and 1940. Moreover, a greater proportion of the population was married (95 percent) during the 1950s than at any time before【B9】. Experts do not agree on why the "marriage rush" of the late 1940s and 1950s occurred, but most social scientists believe it represented a【B10】to the return of peaceful life and prosperity after 15 years of severe economic depression and war.
【B1】
A.rate
B.ratio
C.percentage
D.poll