维护民族团结，必须要尊重少数民族的 ①族长权威②语言文字③宗教信仰④风俗习惯 A

I used to going to the countryside to draw animals and plants. One day I was walking across a field look for rabbits to draw. Losing in thought, I hadn’t noticed a bull to running towards me. About 100 meters ahead was a tree under that I would sit and draw. Suddenly, I heard the noise behind me. I turned and saw the bull. Knowing a bull can run more faster than a man, I quickly reached the tree and climb up. From there I saw the bull kicking my food bag by its feet. It kept done this for 15 minutes and moved away. But I was quite nervous in the tree.

）右图为两分子系统的势能E_p与两分子间距离r的关系曲线。下列说法正确的是      （填选项前的字母）

A．当r等于r₁时，分子间的作用力为零

B．当r小于r₁时，分子间的作用力表现为斥力

C．当r大于r₁时，分子间的作用力表现为引力

D．在r由r₁变到r₂的过程中，分子间的作用力做负功

诊断甲亢最可靠依据是（）

A.甲状腺肿大

B.基础代谢率增高

C.中枢神经系统兴奋性增高

D.T3、T4增高

E.多食、消瘦

下列操作方法，哪个不能增加滤过速度：

A．加压或减压以提高压力差

B．升高药液温度

C．设法使颗粒变细，减少滤饼阻力

D．增大过滤面积

E．加入助滤剂

历史学家通过对甲骨文的研究，能够了解到商代社会的一些情况；通过对《清明上河图》的分析，也能够了解到北宋年间东京汴河沿岸商业的繁荣景象。由此可见，人们对历史的思考和总结，其主要依据是（）

A.历史学家的分析和思考

B.当时的客观事物

C.各种历史教科书

D.各种历史文物