问题 解答题

从一块正方形木板上锯掉2m宽的长方形木条,剩下的面积是48m2,则原来这块木板的面积是______m2

答案

设原来正方形木板的边长为xm.

由题意,可知x(x-2)=48,

解得x1=8,x2=-6(不合题意,舍去).

所以8×8=64.

答:原来这块木板的面积是64m2

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阅读理解

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     CHICAGO(Reuters)-Smoking not only can wrinkle the face and turn it yellow-it can do the same

to the whole body, researchers reported on Monday.

     The study,published in the Archives of Dermatology,shows that smoking affects the skin all over

the body-even skin protected from the sun.

     "We examined non-facial skin that was protected from the sun,and found that the total number of

packs of cigarettes smoked per day and the total. years a person has smoked were linked with the

amount of skin damage a person experienced," Dr. Yolanda Helfrich of the University of Michigan,who

led the study,said in a statement.

     "In participants older than 65 years,smokers had significantly more fine wrinkling than nonsmokers.

Similar findings were seen in participants aged 45 to 65 years. "Helfrich's team added in their report.

     The researchers tested 82 people,smokers and nonsmokers,taking pictures of the inner right atms.

They ranged,in age from 22 to 91 and half were smokers. Independent judges decided how wrinkled

each person's skin was.

     When skin is exposed to sunlight,notably the face,it becomes coarse(粗糙的). Wrinkled and

discolored with a pale yellow tint,Helfrich's team wrote.

     Several previous studies have found that cigarette smoking conduces to premature(过早的)skin

aging as measured by facial wrinkles,the study said,but tittle has been done to measure the aging of skin

not exposed to light.

     The report did not discuss die mechanism involved but previous research has found that cigarette

smoke,among other things,causes blood vessels(血管)beneath the skin to constrict (紧缩),reducing

blood supply to the skin.

     Smoking can also damage the connective tissue that supports both die skin and the internal organs.

1. When your skin is exposed to sunlight long,it becomes all of the following but    .

A. flexible      

B. coarse        

C. rough      

D. discolored

2. What does the underlined phrase"conduces to"in Paragraph 7 mean?

A. help        

B. encourage    

C. prevent      

D. stop

3. How wrinkled a person's skin is doesn't relate to       .

A. the number of cigarettes a person smokes

B. the kind and characteristics of skin

C. how long a person smokes

D. how long skin is under sunlight

4. From the passage smoking results,in skin aging mainly because       .

A. it will lower blood supply to skin    

B. it can make you feel tired

C. it can make skin come off          

D. it can make blood run faster

5. The main purpose of the passage is to        .

A. inform people about the result of the study

B. advise people how to protect skin

C. warn people not to smoke again

D. introduce a new way of avoid skin aging