问题 单项选择题

胆固醇在体内不能转变生成的是

A.维生素D3

B.胆汁酸

C.胆红素

D.雌二醇

E.睾酮

答案

参考答案:C

解析:胆固醇可以:①转变为胆汁酸:胆固醇在肝中转化成胆汁酸(bile acid)是胆固醇在体内代谢的主要去路。正常人每天约合成1~1.5g胆固醇,其中2/5(0.4~0.6g)在肝转变成为胆汁酸,随胆汁排入肠道。②转化为类固醇激素:胆固醇是肾上腺皮质、睾丸、卵巢等内分泌腺合成及分泌类固醇激素的原料。肾上腺皮质细胞中储存大量胆固醇酯,其含量可达2%~5%,90%来自血液,10%自身合成。肾上腺皮质球状带、束状带及网状带细胞可以胆固醇为原料分别合成醛固酮、皮质醇及雄激素。睾丸间质细胞合成睾酮,卵巢的卵泡内膜细胞及黄体可合成及分泌雌二醇及孕酮,三者均是以胆固醇为原料合成的。③转化为7-脱氢胆同醇:在皮肤,胆同醇可被氧化为7-脱氢胆固醇,后者经紫外光照射转变为维生素D3

阅读理解

Welcome to City Lit

About us

City Lit is London’s influential destination for inspiring evening,daytime and weekend courses for adults.Each year we offer thousands of part-time courses,always trying to follow new trends and the passions and interests of our learners.Most of our classes take place in our bright,modern building in Covent Garden and are taught by inspiring tutors,all of whom are leading experts and elites(精英)in their field.

Our courses

City Lit offers you the biggest choice of part-time courses for adults in London.Our courses range from complete beginners to university level to meet your needs.Many lead to a nationally recognized qualification.Our courses run for about 12 weeks.Our courses regularly receive five-star reviews from our learners.

How to enroll(注册)

It’s easy to book a place on a City Lit course.Just follow the steps below or ring our enrollment line on 020 783 1 7831 if you have any enrollment questions.

1.Select a course

Choose a course from over 4,000 that suits your needs.

The information and advice team are on hand to help you with information about courses, careers and financial support.

Opening times:Term time:Weekdays 12:00-19:00

Non-term time:Weekdays 12:00-17:00

2.Check dates &availability

Book in advance to avoid disappointment.Dates,days,times and availability are shown next to each course.

3.Choose enrollment method

By phone:Phone 020 7831 7831;Mon.to Fri.09:00-19:00&Sat.10:00-16:00

In person:Term time:Mon.to Fri.11:00-19:00&Sat.10:00-14:00

Non-term time:Mon.to Fri.12.00-17.00

By post or fax:Some courses require an interview before your enrollment.

You can also visit http:∥www.citylit.ac.uk/enrol to know about the information.

4.Payment&confirmation

You can pay by credit card,debit card,cheque or with cash(in person only).

Please ring enrollments on 020 7831 7831 or visit our enrollment counter for more information.

http:∥www.citylit.ac.uk/enrol

小题1:The main purpose of the passage is ___________.

A.to teach people how to learn well in City Lit

B.to introduce the development of City Lit

C.to tell us some basic information on City Lit

D.to show us some unique courses in City Lit小题2:Which of the following about City Lit is NOT right?

A.There are four different ways to enroll.

B.All teachers of City Lit are excellent.

C.Good comments are given to City Lit.

D.City Lit is a full-time training institution.小题3:The courses City Lit provides __________.

A.can meet people of all ages of all walks of life

B.lead to the worldwide recognized qualification

C.usually last approximately three months

D.are just intended for the very beginners

填空题

甲醇是一种可再生的优质燃料,用途广泛,研究其作用具有广阔前景。

(1)已知在常温常压下,测得反应的反应热如下:

① 2CH3OH(l)+ 3O2(g)  2CO2(g) +4H2O(g)  ∆H1= -1275.6 kJ/mol

② 2CO(g) +O2(g)  2CO2(g)   ∆H2=-566.0 kJ/mol

CH3OH不完全燃烧生成CO和气态水的热化学方程式是       

(2)工业上生产甲醇的反应如下:CO2(g) + 3H2(g)  CH3OH(g)+ H2O(g)   ∆H = -49 kJ/mol

在某温度下,容积均为1 L的A、B两个容器中,按不同方式投入反应物,保持恒温恒容。容器B中经10 s后达到平衡。达到平衡时的有关数据如下表:

容器AB
反应物投入量1 mol CO2(g)和3 mol H2(g)1 mol CH3OH(g)和1 mol H2O(g)
反应能量变化放出αkJ热量吸收19.6 kJ热量
 

①从反应开始至达到平衡时,容器B中CH3OH的平均反应速率为       

②该温度下,B容器中反应的化学平衡常数的数值为       

③α=       

④下列措施能使容器A中甲醇的产率增大的是       

a.升高温度                b.将水蒸气从体系分离

c.用更有效的催化剂        d.将容器的容积缩小一半

(3)我国科学院化学研究所在甲醇燃料电池技术方面获得新突破,组装出了自呼吸电池。甲醇燃料电池的工作原理如下图所示。

① 该电池工作时,b口通入的物质为       

② 该电池正极的电极反应式为