把一个三角形变成和它位似的另一个三角形，若边长缩小了2倍，则面积缩小到原来的 倍．
芯片是所有电脑、“智能家电“的核心部件，它是以高纯度的单质硅（Si）为材料制成的。硅及其氧化物能发生如下反应：高温 高温 ① Si+ O2
下列物质属于同分异构体的一组是 A．CH4与C2H4 B． 与 CH3－CH2－CH2－CH3 C．C2H6与C3H8 D． O2与O3
My knowledge of Hong Kong came only from some movies: a______ of criminals are pursued by the police in the narrow streets and then they have a fight. A. group B. team
Research findings show people spend about two hours dreaming every night, no matter what they have done during the day. A．should B．would C．may D．must
大胆提出‘自秦以来，凡为帝王者皆贼也’的思想家是（ ） A.李贽 B.黄宗羲 C.顾炎武 D.唐甄
柳宗元在《封建论》中说：“秦有天下，裂都会而为之郡邑，废侯卫而为守宰。…….此其所以为得也。”这句话指的是 A．推行分封制 B．设立郡县
