Unit 5 The power of nature Reading课时作业

　　I．单句语法填空

　　1．The students begin their classes at a fixed(fix) time.

　　2．The poem is so complicated that I cannot make out its meaning.

　　3．Chewing(chew) your food well before you swallow is good for your stomach.

　　4．If plastic and rubber are burnt, they'll give off poisonous(poison) gases.

　　5．Before entering a house in some Asian countries, it's good manners(manner) to take off your shoes.

　　6．She didn't dare to go against her father's wishes and went to the art school again.

　　7．The man is infamous(famous) and often does something illegal.

　　8．It is a wonder that he remains alive after dropping from the roof of a ten­storey building.

　　9．The headmaster's requirement(require) is that all the students wear school uniforms at school.

　　10．Some people tried many ways to lose weight, ending up gaining(gain) weight soon again.

　　II．.阅读理解

　　Thousands of years ago people chewed gum in the natural form.The most common ancient chewing gum was tree resin lumps，but people also chewed various sweet grasses，leaves，grains and waxes.Chewing gum has been used in various forms and flavors.

　　 The first commercial chewing gum was made and sold in 1848 by John Bacon Curtis.He called his chewing gum the State of Maine Pure Spruce Gum.John Bacon Curtis and his brother came up with the practical idea of how to make and sell spruce gum as chewing gum.

On July 27，1869，Amos Tyler received the first patent in the United States for chewing gum.However，Tyler never sold his gum commercially.An Ohio dentist，William Finley Semple was honored for this work using the first patent to manufacture