提取蛋白质免疫原的技术有（） A.选择性沉淀 B.超速离心 C.凝胶过滤 D.离子交

被誉为现代经济学之父的亚当·斯密在出版于1759年的《道德情操论》中指出：“如果一个社会的经济发展成果不能真正分流到大众手中，那么它在道义上将是不得人心的，而且是有风险的，因为它注定要威胁社会稳定。”作者的这一提醒主要是为了防止 [ ]

A．劳资矛盾的激化

B．城乡差别的扩大

C．经济危机的发生

D．垄断现象的出现

为提高人大代表审议“一府两院”工作报告的质量，科学地提出代表议案和建议、批评和意见，某市人大常委会对参加2012年“两会”人大代表进行了会前履职培训。这是因为，随着民主和法制建设的发展                                                       

A．人们参与政治生活需要更高的文化素养

B．文化与政治相互交融、不可分开

C．文化生产力在现代经济的总体格局中作用越来越突出

D．文化程度高低越来越成为制约个人政治发展的决定因素

在我国远古社会的传说中，相传（）品尝百草，救民疾苦，发明了原始医药；“耕而作陶”，发明了原始制陶业；教人耕种，出现原始农业和原始文化.

A.黄帝

B.伏羲

C.炎帝

D.唐尧

溶液百分比浓度表示法分为哪几种？

Burkina Faso student teacher Hema Cecile has a lot more time to crack the books thanks to a recent initiative from the World Bank and the International Finance Corporation (IFC). The launch of the Lighting Africa program by the two organizations this year has made it possible for Cecile to swap kerosene lamps for a solar-powered LED lantern.

Lighting Africa is a ＄12 million project which intends to bring light to the poorest regions across sub-Saharan Africa. The program works with the lighting industry to develop clean, affordable lighting and energy solutions for millions without access to electric grids. Its aim is to accelerate the market and to develop education programs that inform off-grid populations currently dependent on costly, inefficient and hazardous fuel-based lighting about modern alternatives.

Cecile used to spend ＄3-4 a month on kerosene for her lamp. That is a large proportion of her earnings—like 70 percent of the population she lives on less than ＄2 a day. In the weeks since buying her lantern she has managed to read four books including Madame Bovary. by Gustave Flaubert and Emile Zola’s Germinal. She is among the most learned in a society which has the world’s lowest literacy rate, according to a 2007 UN Human Development Report. When she graduates next year she will teach in a local junior school She makes ends meet by holiday jobs as a cleaner and an IT trainer. To earn her daily ration of cornmeal she does shifts from May to September in a corn field.

The lanterns are designed to look like the kerosene ones they are replacing in order to increase adoption among the population. Each has a small solar panel on the top and costs an average ＄30, although some cost ＄100, depending on the size of the battery and the number of LED lights it contains.

Because of the large number of sunlight hours in Burkina Faso, the lamps can be relied on to work whenever needed. The battery life is 2-4 years, and can be replaced once they lose their storage capacity. The LED lights last 5-10 years.

Although it is barely out of its trial period the project, Chabanne said there are signs the project is a boon for the population in areas other than household savings and education. "There are fewer people reporting eye problems to the local hospital.

Which one of the following statements is true about Cecile（）

A. She is illiterate, just like many of the citizens in her region.

B. She works only from May to September every year.

C. She is a full time employee in an IT company.

D. She is still a student now