Intuition tests 直觉测试 - 0

Zk从某处看来的问题。一个正四面体和一个棱长与之相等的正四棱锥，将正三角形的面贴合面，棱贴合棱，得到多少面体？

Question from Zk from somewhere ...If we put a face of a regular tetrahedron, to one of the triangle faces of a square pyramid with equilateral triangular sides and same edge length, face to face, edges to edges, then how many faces are there?

5
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Ticketing Price of Beijing Metro 北京地铁的票价

降价，但是没有更高的运能——薄利，却没办法多销。其结果就是总收益降低。的确，没有哪个地铁系统能仅靠自身运营就盈利的，但总不至于连运营成本也打算要财政补贴吧。
要么财政把票价全给补贴了吧，反正政府有的是信用，永远能借到钱。

Lower the price, but no more capacity. Yes, there's no subway system get profit by saling tickets. But should everything including running costs be paid financially?
Finance comes from Tax.

Model DK16A in Taipinghu Depot