点击查看：辽宁各大院校2020年硕士研究生考试成绩查询入口汇总

有关乳腺囊性增生病说法正确的是
A.表现为周期性胀痛 B.一般不用药物治疗 C.可触及颗粒性结节 D.常发生恶变

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 unrelated friends and unrelated 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.
3选？

A.for
B.with
C.on
D.by

下列有关β受体阻滞剂的说法正确的是

A.已经使用ACEI治疗的病人可以不再使用β受体阻滞剂
B. β受体阻滞剂不仅可以减轻心衰症状、降低住院率，还可以降低死亡率
C.对于心力衰竭的治疗卡维地洛优于琥珀酸美托洛尔
D.使用β受体阻滞剂应从小剂量开始，越早越好，不必等到病人水肿消退