题目列表(包括答案和解析)
A microscope is a useful instrument for observing small objects. By producing a bigger image, the microscope reveals details that are undetectable to the naked eye(裸眼).
Before using the microscope, please read the instructions below.
CAUTION: Microscopes are both delicate and expensive and must be handled with care.
1. Always carry the microscope with two hands — one supporting the base and the other on the arm.
2. Avoid stretching the wire of the lamp across a walkway.
3. Keep the stage clean and always use a glass slide for specimens(样本).
4. To avoid crushing the glass slide when focusing, begin with the lens close to the specimen and gradually back off to focus.
5. Keep the microscope covered to prevent the dust while it is being stored.
HOW TO USE THE MICROSCOPE:
1. Plug(接通电源) in the lamp.
2. Place a sample of what you wish to observe on a slide.
3. Adjust the mirror so it reflects light from the room up into the objective lens. When the mirror is correctly adjusted, a complete circle of light iwll appear when you look through the eyepiece.
4. Place your slide with the specimen directly over the center of the glass circle on teh stage. If it is a wet slide, be sure the bottom of the slide is dry.
5. With the LOW POWER objective leans placed over the slide, use the coarse focus knob to lower the lens to the lowest point.
6. Look through the eyepiece with one eye while closing the other eye. Slowly raise the lens until teh focus is relatively clear.
7. Use the fine focus knob to fine -tune(微调)the focus.
8. Without changing the focus knobs, switch to the HIGH POWER objective lens. Once you have switched to HIGH POWER, use only the fine focus knob to make the image sharper.
1.Which of the following is the correct way to use a microscope according to the text?
A．Use one hand to carry the microscope
B．Place a sample directly on the clean stage
C．When stored, the microscope should be adjusted.
D．Look through the eyepiece with one eye.
2.If you want to observe a thin piece of hair, which of the following should you do first.?
A．Switch to objective lens. B．Adjust the mirror.
C．Look through the eyepiece. D．Place the hair on a glass slide.
3.According to the text, you could see a complete circle of light _____.
A．after correctly adjusting the mirror
B．while looking at the specimen on a glass slide
C．after slowly raising the objective lens
D．before positioning the mirror correctly
A microscope is a useful instrument for observing small objects. By producing a bigger image, the microscope reveals details that are undetectable to the naked eye(裸眼).
Before using the microscope, please read the instructions below.
CAUTION: Microscopes are both delicate and expensive and must be handled with care.
1. Always carry the microscope with two hands — one supporting the base and the other on the arm.
2. Avoid stretching the wire of the lamp across a walkway.
3. Keep the stage clean and always use a glass slide for specimens(样本).
4. To avoid crushing the glass slide when focusing, begin with the lens close to the specimen and gradually back off to focus.
5. Keep the microscope covered to prevent the dust while it is being stored.
HOW TO USE THE MICROSCOPE:
1. Plug(接通电源) in the lamp.
2. Place a sample of what you wish to observe on a slide.
3. Adjust the mirror so it reflects light from the room up into the objective lens. When the mirror is correctly adjusted, a complete circle of light iwll appear when you look through the eyepiece.
4. Place your slide with the specimen directly over the center of the glass circle on teh stage. If it is a wet slide, be sure the bottom of the slide is dry.
5. With the LOW POWER objective leans placed over the slide, use the coarse focus knob to lower the lens to the lowest point.
6. Look through the eyepiece with one eye while closing the other eye. Slowly raise the lens until teh focus is relatively clear.
7. Use the fine focus knob to fine -tune(微调)the focus.
8. Without changing the focus knobs, switch to the HIGH POWER objective lens. Once you have switched to HIGH POWER, use only the fine focus knob to make the image sharper.
【小题1】Which of the following is the correct way to use a microscope according to the text?
| A．Use one hand to carry the microscope |
| B．Place a sample directly on the clean stage |
| C．When stored, the microscope should be adjusted. |
| D．Look through the eyepiece with one eye. |
| A．Switch to objective lens. | B．Adjust the mirror. |
| C．Look through the eyepiece. | D．Place the hair on a glass slide. |
| A．after correctly adjusting the mirror |
| B．while looking at the specimen on a glass slide |
| C．after slowly raising the objective lens |
| D．before positioning the mirror correctly |
Don't blame genes for aging facial skin. A new study of twins suggests you can 1 those coarse(粗糙的) wrinkles, brown or pink spots, and dilated(膨胀的) blood vessels on too much time in the sun, smoking, and being overweight.
Because twins share genes, but may have 2 exposures to environmental factors, studying twins allows an, "opportunity to control for genetic susceptibility(敏感性)," Dr. Elma D. Baron, at Case Western Reserve School of Medicine in Cleveland, Ohio, and colleagues 3 in the latest issue of Archives of Dermatology.
Their analysis of environmental skin-damaging factors in 65 pairs of twins hints that skin aging is 4 more to environment and lifestyle than 5 factors.
But when it 6 skin cancer, the researchers say their findings support previous reports that 7 environment and genes affect skin cancer risk.
Baron's team 8 facial skin of 130 twins, 18 to 77 years old, who lived 9 in the northern Midwest and Eastern regions of the U.S. who were 10 the Twins Days Festival in Ohio in August 2002.
At this time, each of the twins also 11 reported how their skin burned or tanned 12 sunscreen(防晒霜), their weight, and their history of skin cancer, smoking, and alcohol drinking.
The study group 13 of 52 fraternal and 10 identical twin pairs, plus 3 pairs who were unsure of their twin status. Identical(同卵的) twins share all of their genes and fraternal twins share only about half.
From these data, the researchers 14 strong ties, outside of twin status, between smoking, older age, and being overweight, and having facial skin with evidence of environmental 15
16 contrast, sunscreen use and drinking alcohol appeared correlated with 17 skin damage.
Baron and colleagues say the current findings, which highlight ties between facial 18 and potentially avoidable 19 factors -- such as smoking, being overweight, and 20 overexposure to the sun's damaging rays -- may help motivate people to minimize these risky behaviors.
( ) 1. A. blame B. owe C. take D. bring
( ) 2. A. same B. different C. similar D. common
( ) 3. A. explain B. confirm C. declare D. shout
( ) 4. A. equal B. related C. close D. strict
( ) 5. A. characteristic B. personal C. natural D. genetic
( ) 6. A. comes to B. talks of C. refers to D. gets to
( ) 7. A. all B. neither C. both D. either
( ) 8. A. examined B. checked C. inspected D. interviewed
( ) 9. A. most B. usually C. mostly D. always
( ) 10. A. joining B. representing C. attending D. remarking
( ) 11. A. separately B. lonely C. commonly D. truly
( ) 12. A. with B. on C. in D. without
( ) 13. A. consisted B. made up C. contained D. included
( ) 14. A. documented B. recorded C. reported D. noted
( ) 15. A. damage B. exploration C. protection D. material
( ) 16. A. In B. By C. As D. At
( ) 17. A. lesser B. more C. no D. fewer
( ) 18. A. look B. aging C. expression D. wrinkle
( ) 19. A. environmental B. genetic C. emotional D. psychological
( ) 20. A. protected B. planned C. unprotected D. prevented
.
CHICAGO (Reuters) - Smoking not only can wrinkle(起皱纹) 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 arms. 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, wrinkled and discolored with a pale yellow tint, Helfrich's team wrote.
Several previous studies have found that cigarette smoking contributes to premature（过早的）skin aging as measured by facial wrinkles, the study said, but little has been done to measure the aging of skin not exposed to light.
The report did not discuss the 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 the skin and the internal organs.
66. The best title for this passage would be_______.
A. The danger of smoking B. A survey of smokers
C. Quit smoking for health D. Smoking causes skin aging
67. how wrinkled each person's skin 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
68. It can be inferred from the study _______.
A. smoking won’t make skin protected from the sun age
B. smoking will do damage to skin rather than other organs
C. smokers over 65 usually won’t worry about their skin
D. the age of smokers is not connected with the result of the test
69. 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
70. The main purpose of the passage is to ______.
A. inform people about the result of the study
B. advise people to how to protect skin
C. warn people not to smoke again.
D. introduce a new way of avoid skin aging
CHICAGO （Reuters） - Smoking not only can wrinkle （起皱纹） the face and tarn 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 p
articipants 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 arms． 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, wrinkled and discolored with a pale yellow tint, Helfrich ' s team wrote．
Several previous studies have found that cigarette smoking contributes to premature（过早的）skin aging as measured by facial wrinkles, the study said, but little 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,．
【小题1】When your skin is exposed to sunlight long, it-becomes all of the following but _____．
| A．flexible | B．coarse | C．rough | D．discolored |
| 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 |
| 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 |
| 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 |
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