The coins weren't so valuable to me, but they did matter to her. I just performed a little kindness. I was happy.

　　　5．How might the author probably use the money when he saved enough pennies as a child?

　　　A．Put it aside. B．Buy some snacks.

　　　C．Use it to mail a letter. D．Use it to help others in need.

　　　6．When grown up, the author was still happy to pick up coins because .

　　　A．he could become rich with the coins

　　　B．coins were much easier to find than dollars on the ground

　　　C．he still believed the story about coins

　　　D．he could use the coins to buy some little things

　　　7．The underlined phrase in paragraph 2 means ______.

　　　A．in addition B．selecting something carefully

　　　C．as well D．doing useless work in the end

　　　8．What can we learn from this passage?

　　　A．Doing small acts of kindness is good.

　　　B．Every coin has two sides.

　　　C．We should value money, even coins.

　　　D．Chance favors only the prepared mind.

　　　Try this: For an entire day, forget about the clock. Eat when you're hungry and sleep when you're tired. What do you think will happen?

　　　You may be surprised to find that your day is much like most other days. You'll probably get hungry when you normally eat and tired when you normally sleep. Even though you don't know what time it is, your body does.

　　　These patterns(模式) of everyday life are called circadian rhythms, in other words, our body clocks. And they are no more than habits. Inside our bodies are several clocklike systems that follow a roughly 24-hour cycle. Throughout the day and night, our inner clocks direct changes in temperature, body chemicals, hunger, sleepiness and more. Everyone's rhythms are different, which is why you might like to stay up late while your sister always wants to go to bed early.

　　　Learning about our body clocks may help scientists understand why problems arise when we act out of step with our circadian rhythms. For example, traveling across time zones can make people wake up in the middle of the night. Regularly staying up late can make students do worse in tests.

　　　"There is a growing sense that when we eat and when we sleep are important parts of how healthy we are," says Steven Shea, director of the Sleep Disorders Program at Brigham.

　　　One way to learn about how our body clocks work is to mess(弄乱) them up and see what happens. That's what neurologist Frank Scheer and his workmates did in a recent study.Their study suggests that staying up night after night could make kids extra hungry and more likely to gain weight. And regularly sleeping too little, Scheer says, may be one cause of the recent increase in childhood obesity (肥胖).

　　　9．What will happen if you forget about the clock according to the passage?

　　　A．You will feel upset.

　　　B．Your body will behave as usual.

　　　C．Your body will not know what time it is.

　　　D．You will probably get hungry more easily.

　　　10．Which one is NOT true about body clocks according to the passage?

　　　A．They control changes in our temperature, body chemicals, hunger, and sleepiness.

　　　B．People's body clocks are different from each other.

　　　C．Our body clocks will change according to the changes of everyday schedule.

　　　D．More people are coming to realize body clocks are important for our health.

　　　11．How do Frank Scheer and his workmates study body clocks?

　　　A．By seeing what happens when they are messed up.

　　　B．By asking questions and collecting answers.

　　　C．By studying people traveling across time zones.

　　　D．By studying children who suffer from childhood obesity.

　　　Wanda Butts dropped the phone and screamed when she heard the news that her son was dead. Josh had drowned(溺亡) while sailing on a lake with friends. The 16-year-old didn't know how to swim, and he wasn't wearing a life jacket.

　　　Josh was not alone in the black community. USA Swimming points that 70% of African-American children cannot swim. According to an official survey, African-American children between the ages of 5 and 14 are three times more likely to drown than white children in the same age range.

In 2007, Butts started the Josh Project, a non-profit(非营利组织) that provides low-cost swimming lessons for children in Toledo, Ohio. The swimming lessons take place at a local high school over four Saturdays for a total of 10$. Up to now, the Josh Project has helped more than 1,000 children learn how to swim.