叙述并证明余弦定理．

右图是a、b、c三种物质的溶解度曲线．由图示判断下列说法中不正确的是（　　）

A．在t₁℃时，a的溶解度等于c的溶解度

B．c的溶解度随温度的升高而减少

C．a的饱和溶液从t₂℃降温至t₁℃时变为不饱和溶液

D．当a中含有少量b时，可以用降温结晶的方法提纯a

患者女性，38岁，双颊黏膜白色病变1年。活检标本见上皮萎缩，表面不全角化，上皮钉突呈不规则延长，基底细胞层液化变性，固有层内近上皮区域见淋巴细胞浸润带。病理诊断为

A．慢性盘状红斑狼疮

B．寻常性天疱疮

C．扁平苔藓

D．良性黏膜类天疱疮

E．念珠菌病

以下信息属于我国文化建设成就的是

A．全国已有1743家公共博物馆、纪念馆等向社会免费开放

B．到2010年底，中国特色社会主义法律体系已经形成

C．目前，中国已建成投入运营的高铁总里程超过7500公里，居世界第一位

D．我国积极实施节能产品惠民工程，大力推广节能空调、高效照明灯具等

举例说明细胞黏附分子介导细胞黏附的主要方式有几种？

With the spread of inter-active electronic media a man alone in his own home will never have been so well placed to fill the inexplicable mental space between cradle and crematorium. So I suspect that books will be pushed more and more into those moments of travel or difficult defecation (1) people still don’t quite know what to do with.

When people do read, I think they’ll want to feel they are reading literature, or (2) something serious. (3) you’re going to find fewer books presenting themselves as no- nonsense and (4) assuming literary pretensions and being packaged as works of art. We can expect an extraordinary variety of genre, but with an underlying (5) of sentiment and vision.

Translators can only (6) from this desire for the presumably sophisticated. We can look forward to lots of difficult names and fantastic stories of foreign parts enthusiastically (7) by the overall worship of the "global village" Much of this will be awful and some wonderful, (8) don’t expect the press or the organizers of prizes to offer you much help in making the appropriate distinctions. They will be chiefly (9) in creating celebrity, the greatest enemy of discrimination, but a good prop for the (10) consumer.

Every ethnic grouping over the world will have to be seen to have a great writer--a phenomenon that will (11) a new kind of provincialism, more chronological than geographic, (12) only the strictly contemporary is talked about and (13) . Universities, including Cambridge, will include (14) their literature syllabus novels written only last year. (15) occasional exhumation for the Nobel, the achievements of ten or only five years ago will be largely forgotten.

In short, you can’t go too far wrong when predicting more of the same. But there is a (16) side to this--the inevitable reaction against it. The practical things I would like to see happen--publishers seeking less to (17) celebrity through extravagant advertising, (18) and magazines (19) space to reflective pieces--are rather more improbable than the Second Coming (耶稣复临). But dullness never quite darkens the whole planet. In their own idiosyncratic fashion a few writers will (20) be looking for new departures.

7（）

A.contaminated

B.contained

C.sustained

D.maintained