阅读理解
    Tom lives in the UK. His friend Jack is in Dubai. He will go to see his friend. First he needs to go to London to take the plane.
    On Friday morning, Tom takes a bus to the train station. It takes Tom about 30 minutes to get there. Tom gets on the train at about 10 o'clock：The train leaves at 10：15. The train trip to London takes three hours. At lunchtime Tom gets to London. Tom eats a hamburger for lunch. Then he goes to the airport(机场)by subway. After about one hour,Tom gets to the airport. Tom gets on the plane at 8 o'clock in the evening. The trip takes a long time. Tom is tired(疲倦的)after a busy day. So he goes to sleep(睡觉). On Saturday morning, Tom gets to Dubai. He is very happy, because he will have a great time with his friend.

不管化学反应过程是一步完成还是分为数步完成，这个过程的热效应是相同的。
已知：H₂O(g)===H₂O(l)　ΔH₁＝Q₁ kJ/mol①
C₂H₅OH(g)===C₂H₅OH(l)　ΔH₂＝Q₂ kJ/mol②
C₂H₅OH(g)＋3O₂(g)===2CO₂(g)＋3H₂O(g)　ΔH₃＝Q₃ kJ/mol③
若使23 g酒精液体完全燃烧，最后恢复到室温，则放出的热量为(　　)

图中是对顶角量角器，用它测量角的原理是 ____.

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观察下面四幅建筑物图片，回答下题。位于北京的建筑物是（  ）

如图，△ABC中BC边上的高为h₁，AB边上的高为h₂，△DEF中DE边上的高为h₃，下列结论正确的是（   ）