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已知如下结论：“等边三角形内任意一点到各边的距离之和等于此三角形的高”，将此结论拓展到空间中的正四面体（棱长都相等的三棱锥），可得出的正确结论是：______

答案

∵等边三角形内任意一点到各边的距离之和等于此三角形的高，

根据平面三角形中此结论拓展到空间中的正四面体可得：

正四面体内任意一点到各个面的距离之和等于此正四面体的高，

故答案为正四面体内任意一点到各个面的距离之和等于此正四面体的高．

单项选择题

楼地面工程整体面层施工后，养护时间不应少于（）d；抗压强度应达到5MPa后方准上人行走；抗压强度应达到设计要求后，方可正常使用。

A.7

B.10

C.14

D.28
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In the following passage, there are 20 blanks representing the words that are missing from the context. You are to put back in each of the blanks the missing word． The time for this section is 20 minutes.
Where do you really come from And how did you get (1) where you live today DNA studies suggest that all humans today (2) from a group of African ancestors who—about 60,000 years ago— (3) a remarkable journey.
The Genographic Project is seeking to chart new (4) about the migratory history of the human species by (5) sophisticated laboratory and computer analysis of DNA contributed by hundreds of (6) of people from around the world． In this unprecedented and real-time (7) effort, the Genographic Project is closing the gaps of what science (8) today about mankind’s ancient migration stories.
The Genographic Project is a five-year (9) partnership led by National Geographic Explorer-in-Residence Dr. Spencer Wells. Dr. (10) and a team of renowned international scientists and IBM researchers, are (11) cutting-edge genetic and computational technologies to analyze historical patterns in DNA (12) participants around the world to better understand our human genetic roots. (13) three components of the project are: to gather field research data (14) collaboration with indigenous and traditional peoples around the world; to invite (15) general public to join the project by purchasing a Genographic Project Public Participation Kit; (16) to use proceeds from Genographic Public Participation Kit sales to further (17) research and the Genographic Legacy Fund which in (18) supports indigenous conservation and revitalization projects. The Project is anonymous, non-medical, (19) , non-profit and non-commercial and all results will be placed in the (20) domain following scientific peer publication.

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