山 It is 1:45 am. Imagine you are studying for an
important exam. You have to take it this afternoon. To
stay awake and alert, you drank two cups of coffee in
the last three hours. You are now drinking a popular
energy drink.
回 Caffeine is the world's most popular chemical that
changes our mood. It gives us a burst of power to
decrease physical tiredness and increase alertness。It
is found not only in coffee, tea, and energy drinks, but
also in pain relievers and chocolate bars.
目 Many societies have created particular social
rituals around the use of caffeine: afternoon tea in the
U.K., the cafe culture of France, and the tea ceremony
in Japan.
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