题型：单选题难度：★★★★★13.6万热度
下列哪项说法不符合胸腺生理功能
A．产生淋巴细胞
B．造血功能
C．储血功能
D．滤血功能
E．免疫反应
该题目是单项选择题，请记得只要选择1个答案！
A、对
B、错
（）是具有造血、滤血、储血、免疫功能的生理器官
A．脾B．肝C．肾D．胆
下列关于脾脏的功能说法正确的是()
A、免疫细胞定居的场所
B、T细胞占40%,B细胞占60%
C、免疫应答发生的场所
D、储血、滤血及造血功能
E、成生物活性物质,并贮存红细胞
A产生抗体和效应淋巴细胞
B边缘区和脾索有滤血功能
C脾脏可储存部分血细胞
D脾小体可分泌激素
E严重缺血时可恢复造血功能
下列关于脾脏的叙述哪项是正确的
A.脾脏具有滤血、造血、储血及参与免疫反应等多种功能
B.新鲜脾切面大部分呈暗红色称为红髓
C.白髓包括中央动脉周围淋巴鞘与脾小结
D.以上均是
3～6个月胚胎的主要造血器官是
A．肝脏
B．脾脏
C．卵黄囊
D．骨髓
E．胸腺
关于胚胎期造血，下列选项错误的是
A．卵黄囊壁上的血岛是人类最初的造血中心
B．肝脏造血是由卵黄囊血岛的造血干细胞迁移到肝脏而引起的
C．第5个月以后骨髓成为胚胎的造血中心
D．淋巴结不参与胚胎期造血
E．胚胎发育第5周造血干细胞经血流入脾，在此增殖、分化和发育
关于红骨髓下列正确的是
A．含大量各阶段血细胞而呈现红色
B．18岁后红骨髓仅存在于扁骨、短骨及长管骨的近心端
C．红骨髓约占骨髓总量的50％
D．红骨髓是脂肪化的骨髓
E．在正常情况下不再参与造血，但仍保留造血潜能
下列哪项符合脐血中的造血干／祖细胞
A．CD34+细胞占有核细胞百分数的0．5％～1．5％
B．CD34+细胞占有核细胞百分数的0．05％～0．15％
C．CD34+细胞占有核细胞百分数的0．1％
D．CD34+细胞有12％～13％的细胞处在S／G2M期
血细胞分化是指
A．分化过程是可逆的
B．分裂后产生新的子细胞在生物学性状上产生了新的特点
C．通过特定基因的表达合成了特定的蛋白质
D．血细胞失去某些潜能、转变为具有新功能细胞的过程
E．分化后的新细胞与原来的细胞有了质的不同
比重是指单位体积物体的重量。
此题为判断题(对，错)。！
磁铁的两端最强的地方叫“磁性”。
A
EventhougheducationiscompulsoryforchildrenintheUnitedStates,itisnotcompulsoryforthemtogotoaconventionalschooltogetthateducation.ineveryoneofthe50states,itislegalforparentstoeducatetheirchildrenathome,orto"homeschool"theirchildren.Althoughnostaterequiresparentstohavespecialtrainingtohomeschooltheirchildren,theregulationsparentsmustfollowvarywidelyfromstatetostate.NewJersey,forexample,imposesvirtuallynorequirements.Incontrast,NewYorkrequireshomeschoolerstonotifytheirschooldistricts,fileinstructionalplansandfrequentreports,andsubmittheresultsoftestsorotherformsofassessmentforeachchild.
B
IncreasingnumbersofAmericanfamilieshavebeenoptingforhomeschooling.AccordingtotheNationalCenterforEducationalStatistics,about1.1millionchildrenwerebeinghomeschooledinthespringof2003.Thisrepresentsanincreasefromthe850,000whowerebeinghomeschooledinthespringof1999.Inaddition,thehome-schoolingrate-thepercentageoftheschool-agepopulationthatwasbeinghomeschooled-increasedfrom1.7percentin1999to2.2percentin2003.
C
Asurveyconductedin2003askedparentstogivetheirmostimportantreasonsforhomeschoolingtheirchildren.Thirty-onepercentcitedconcernsabouttheenvironmentinconventionalschools,includingsafety,drugs,ornegativepeerpressure.Thirtypercentsaidthatthemostimportantreasonwastoprovidereligiousormoralinstruction.Sixteenpercentsaidthatthemostimportantreasonwasdissatisfactionwithacademicinstructionatconventionalschools.Parentsgaveotherreasons,too;forinstance,manysaidthattheywantedtostrengthenfamilybondsorallowtheirchildrenmorefreedom.
D
Itisdifficulttoshowwhetherconventionalschoolingorhomeschoolingworksbetter.Home-schooledchildrentendtoscoresignificantlyhigherthanthenationalaverageoncollegeentrancetests.Buteducatorssaythatitisn'teasytodeterminehowmeaningfulthefiguresare,giventhecomplexitiesofmakingdirectcomparisons.Inthedebateabouthomeschooling,socializationismoreofanissuethanachievement.Advocatesofconventionaleducationbelievethathome-schooledchildrenareatadisadvantagebecausetheymissoutonthekindsofsocialinteractionandrelationshipswithpeersthatareanessentialpartofatotaleducation.Advocatesofhomeschoolingsaythathome-schooledchildrenarenotsociallyisolated;theythinkthathome-schooledchildrenhavealargersocialstructurebecausetheycanbeoutintheworld,incontactwithpeopleofdifferentages,andhavingexperiencesthattheycouldneverhaveinconventionalschools.
Questions1-5Choosethebeststatement(A.B,CorD)foreachsentence.
A.relatingtoameeting
B.followingwhatisnormalorusual
C.followingareligion
D.educational
A.Ineveryoneofthe50states,itislegalforparentstoeducatetheirchildrenathome.
B.Thirty-onepercentofparentssaythatthemostimportantreasonforhomeschoolingisconcernsabouttheenvironmentinconventionalschools.
C.Thenumberofchildrenwhowerebeinghomeschooledincreasedfrom850,000in1999toabout1.1millionin2003.
D.Asurveywasconductedin2003.
A.1.1million
B.30percent
C.16percent
D.2.2percent
A.Home-schooledchildrenareatadisadvantagebecausetheymissoutonsomekindsofsocialinteractionandrelationships.
B.Thirtypercentofparentswhohomeschooltheirchildrensaidthatthemostimportantreasonwastoprovidereligiousormoralinstruction.
C.Thehome-schoolingrateincreasedfrom1.7percentin1999to2.2percentin2003.
D.TheregulationsthatparentsofhomeschoolersmustfollowvarywidelyfromStatetostate.