柴胡、葛根、升麻都具有的功效是（） A.透发麻疹 B.生津止渴 C.和解退热 D.升

Mark Twain once observed that giving up smoking is easy. He knew, because he’d done it hundreds of times himself. Giving up for ever is a trifle more difficult, apparently, and it is well known that it is much more difficult for some people than for others. Why is this so

Few doctors believe any longer that it is simply a question of will power. And for those people that continue to view addicts as merely "weak", recent genetic research may force a rethink. A study conducted by Jacqueline Vink, of the Free University of Amsterdam, used a database called the Netherlands Twin Register to analyze the smoking habits of twins. Her results, published in the Pharmacogenomics Journal, suggest that an individual’s degree of nicotine dependence, and even the number of cigarettes he smokes per day, are ply genetically influenced.

The Netherlands Twin Register is a voluntary database that contains details of some 7,000 pairs of adult twins (aged between 15 and 70 ) and 28,000 pairs of childhood twins. Such databases are prized by geneticists because they allow the comparison of identical twins (who share all their genes) with fraternal twins (who share half). In this case, however, Dr. Vink did not make use of that fact. For her, the database was merely a convenient repository of information. Instead of comparing identical and fraternal twins, she concentrated on the adult fraternal twins, most of whom had completed questionnaires about their habits, including smoking, and 536 of whom had given DNA samples to the register.

The human genome is huge. It consists of billions of DNA "letters", some of which can be strung together to make sense (the genes) but many of which have either no function, or an unknown function. To follow what is going on, geneticists rely on markers they have identified within the genome. These are places where the genetic letters may vary between individuals. If a particular variant is routinely associated with a particular physical feature or a behavior pattern, it suggests that a particular version of a nearby gene is influencing that feature or behavior.

Dr. Vink found four markers which seemed to be associated with smoking. They were on chromosomes 3, 6, 10 and 14, suggesting that at least four genes are involved. Dr. Vink hopes that finding genes responsible for nicotine dependence will make it possible to identify the causes of such dependence. That will help to classify smokers better (some are social smokers while others are physically addicted) and thus enable "quitting" programs to be customized.

Results such as Dr. Vink’ s must be interpreted with care. Association studies, as such projects are known, have a disturbing habit of disappearing, as it were, in a puff of smoke when someone tries to replicate them. But if Dr. Vink really has exposed a genetic link with addiction, then Mark Twain’s problem may eventually become a thing of the past.

The major difference between Dr. Vink and other geneticists is that（）

A. her research is not based on the study of twins but on questionnaires

B.her research does not emphasize the contrast between two kinds of twins

C. her research is interested in the smoking habits of fraternal twins

D. her research only focuses on the study of the DNA of adult twins

据统计，每年世界上银总消耗量的40%用于感光材料的生产，感光材料经曝光、显影、定影后,黑白片上的银80%左右进入定影液,彩色片上的银几乎全部进入废定影液，所以废定影液中银的含量是十分惊人的。

某研究性学习小组拟对某照相公司的废定影液进行实验处理，回收其中的银和溴。

（一） 资料支撑：

① 定影液(硫代硫酸钠，Na₂S₂O₃)跟胶片或相纸上没有感光部分的溴化银反应，反应方程式为：AgBr(s)+  2Na₂S₂O₃(aq) = Na₃[Ag(S₂O₃)₂](aq) + NaBr(aq)。

② 在酸的作用下，Na₃[Ag(S₂O₃)₂]能转化为不溶性的Ag₂S。反应原理为：

6HCl+2Na₃[Ag(S₂O₃)₂]=6NaCl+Ag₂S↓+3S↓+3SO₂↑+H₂SO₄+2H₂O。

③溶液中有少量溴化银，可用锌将其还原出来。

（二） 实验程序设计

（三） 试回答下列问题

（1）本实验需用6mol/L的盐酸250mL，配制时除需量筒、烧杯、玻璃棒外，还需用的仪器有：                、                     。

　（2）指出流程图中操作所包含的装置是（填序号：A、B、C）Ⅰ    Ⅱ    Ⅲ    。

（3）步骤③是在空气中灼烧的。该反应的化学方程式：                          。实验操作时，加入适量的硝酸钾加盖后再灼热，加硝酸钾的目的可能是：         。

（4）加入锌粉发生的离子反应为：                      。

抗震设计用的地震影响曲线中，反映地震震级、震中距和场地类别等因素的下降段起点对应的周期值为（）。

A.地震活动周期

B.设计特征周期

C.结构自震周期

D.地基固有周期

为什么说减数分裂是生物多样性的基础？

实验室常用王水的组成是（）。

A.1体积HCl+1体积HNO

B.1体积Hcl+3体积HNO

C.3体积Hcl+1体积HNO