1
Although April did not bring
us the rains we all hoped for, and
although the Central Valley doesn't generally
experience the sound and lightning that
can go with those rains, it's still important for parents to be able to answer
the youthful questions about thunder
and lightning.
The reason these two wonders of nature
are so difficult for many adults to explain to children is that they are
not very well understood by adults themselves. For example, did you know that
the lightning we see flashing down to
the earth from a cloud is actually flashing up to a cloud from the earth? Our
eyes trick us into thinking we see a downward motion when it's actually the
other way around. But then, if we
believed only what we think and we see, we'd still insist that the sun rises in the monring and sets at night.Most
lightning flashes take place inside a cloud, and only a relative few can be seen jumping between two clouds or between
earth and a cloud. But, with about 2,000
thunderstorms taking place above the earth every minute of the day and night,
there's enough activity to produce about 100 lightning strikes on earth every
second.
Parents can use thunder and lightning to help their children
learn more about the world around them. When children understand that the light
of the lightning flashing reaches their eyes almost at the same moment, but the sound of the thunder takes about 5
seconds to travel just one mile, they can begin to time the interval(间隔) between the flash
and the crash to learn how close they were to the actual spark(闪光).
2
How many of you drink cola?
Nearly everyone. Did you know that cola started out not as a soft drink but as
a cure for headaches back in the late
1800s? John S. Pemberton, a druggist from Atlanta,
had experimented for many months trying to find a cure for the common headache. He worked in his backyard, mixing and heating different
combinations of oils and flavors until he found one that seemed promising.
Pemberton bottled the mixture and
began selling it in drugstores as concentrated syrup that the customer had to mix with water before
drinking.Cola’s transformation from medicinal
syrup to a carbonated soft drink came about quite by accident. One day, a customer came into a drugstore complaining of
a headache and asked for a bottle of
cola syrup. He wanted to take it right away. So he asked the clerk to mix the medicine while he waited. The clerk,