文档介绍：考研英语一历年真题及答案
【篇一：考研英语一真题及答案详细解析】
ass=txt>全国研究生研究生入学统一考试英语（一）试题
及答案详细解析
section i use of english :
directions：read the following text. choose the best word(s) for each numbered blank and mark a，b,c or d on the answer sheet. (10 points)
though not biologically related，friends are as ―related‖ as fourth cousins，sharing about 1% of genes. that is _(1)_a study，published from the university of california and yale university in the proceedings of the national academy of sciences，has__(2)_.
the study is a genome-wide analysis conducted _(3)__1,932 unique subjects which __(4)__pairs of uelated friends and uelated strangers. the same people were used in both_(5)_.
while 1% may seem_(6)_,it is not so to a geneticist. as james fowler，professor of medical genetics at uc san diego，says，―most people do not even _(7)_their fourth cousins but somehow manage to select as friends the people who_(8)_our kin.‖
the study_(9)_found that the genes for smell were something shared in friends but not genes for immunity .why this similarity exists in smell genes is difficult to explain，for now,_(10)_,as the team suggests，it draws us to similar environments but there is more_(11)_it. there could be many mechanisms working together that _(12)_us in choosing genetically similar friends_(13)_‖functional kinship‖ of being friends with_(14)_!
one of the remarkable findings of the study was the similar genes seem to be evolution_(15)_than other genes studying this could help_(16)_why human evolution picked pace in the last 30,000 years，with social environment being a major_(17)_factor.
the findings do not simply explain people‘s_(18)_to befriend those of similar_(19)_backgrounds，say the researchers. though all the subjects were drawn from a population of european extraction，care was taken to_(20)_that all subjects，friends and strangers，were taken from the same population.
1. [a] when [b] why [c] how [d] what
2. [a] defended [b] concluded [c] withdrawn [d] advised
3.