Text 1
Cinderella
Long, long time ago ,there lived a beautiful girl named Cinderella. because her parents passed away ,she lived with her step mother and step sister. Cinderella was very sad everyday because she had to do the housework alone.
one day, the king wanted to find the wife for his son .he invited all the beautiful girls to come. cinderella was very sad because her step sister did not let her go. her sister went to the palace without Cinderella.
luckily, the angel came and helped Cinderella to go to the palace. in the palace, Cinderella danced with the prince. he fell in love with her: then he married her. they lived happily ever after
Text 2
A brief summary of speech production
speech production is made possible by the specialized movements of our vocal organs that generate speech sound waves.
like all sound productions, speech production requires a source of energy. the source of energy for speech production is the steady stream of air that comes from the lungs as we exhale. when we breathe normally, the air stream is inaudible. to become audible, the air stream must vibrate rapidly. the vocal cords cause dies air stream to vibrate.
as we talk, the vocal cords open and close rapidly, chopping up the steady air stream into a series of puffs. the puffs are heard as a buzz, but this buzz is still not speech.
to produce speech sounds, the vocal tract must change shape. during speech, we continually alter the shape of the vocal track by moving the tongue and lips, etc. these movement change the acoustic properties of vocal track, which in turn produce the different sounds of speech.
Text 3
Gene splicing
genetic research has produced both exciting and frightening possibilities. scientist are now able to create new forms of life in the laboratory due to the development of gene splicing.
on the one hand, the ability to create life in the laboratory could greatly benefit mankind.
for example , because its very expensive to obtain insulin from natural sources, scientist have developed a method to manufacture it inexpensively in the laboratory.
another beneficial application of gene splicing is in agriculture.
scientists foresee the day when new plants will be developed using nitrogen from the air instead of from fertilizer. therefore, food production could be increased. in addition , entirely new plants could be developed to feed the world’s hungry people.