如图所示，为一环境温度监控电路，R₁为灯泡，R₂为半导体材料制成的热敏电阻（电阻随温度升高而变小）．当环境温度降低时灯泡的亮度变____ （填“亮”或“暗”）．电路中消耗的总功率P变____ （填“大”或“小”）．

若x=4，则|x﹣5|=____ 

    Big Ben is not the name of a man. It's the name of a big clock in London. This clock has four faces. So, no matter(无论)where you stand, you can read the time on the face of Big Ben. Each face is the size of a bus. The hands are about four metres long. If you go to London, you may want to visit the Houses of Parliament(英国国会大厦). In that place you will find Big Ben sits at the top of the clock tower in the Houses of Parliament. You will probably hear it and see it. The big clock makes such a loud noise. It goes every quarter of an hour. Big Ben has been the most famous symbol(标志)of  London