—Did you remember to give Mary the money you owed her?
—Yes. I gave it to her ________I saw her.
A．while B．the instant C．suddenly D．once
_____ to finish this composition in such a short time is a mystery.
A．How did he manage B．What did he manage
C．How he managed D．What he managed
Einstein’s most famous theory is ______ we call the Theory of Relativity.
A．what B．that C．which D．why
Not everyone has realized what ________important part the balance of ________nature plays in their life.
A．an；the B．/；the C．an；/ D．the；/
Camping wild is a wonderful way to experience the natural world and, at its best, it makes little environmental influence. But with increasing numbers of people wanting to escape into the wildness, it is becoming more and more important to camp unobtrusively(不引人注目的) and leave no mark.
Wild camping is not permitted in many places, particularly in crowed lowland England. Wherever you are, find out about organizations responsible for managing wild spaces, and contact them to find out their policy about camping and shelter building. For example, it is fine to camp wild in remote parts of Scotland, but in England you must ask the landowner’s permission, except in national parks
Camping is about having relaxation, sleeping outdoors, experiencing bad weather, and making do without modern conveniences. A busy, full-equipped campsite seems to go against this, so seek out smaller, more remote places with easy access to open spaces and perhaps beaches. Better still, find a campsite with no road access: walking in makes a real adventure.
Finding the right spot to camp is first step to guaranteeing a good night’s sleep. Choose a campsite with privacy and minimum influence on others and environment. Try to use an area where people have obviously camped before rather than creating a new spot. When camping in woodland, avoid standing dead trees, which may fall on a windy night. Avoid animal runs and caves and possible homes of biting insects. Make sure you have most protection on the windward side. If you make a fire, do so downwind of your shelter. Always consider what influence you might have on the natural world. Avoid damaging plants. A good campsite found, not made-changing it should be unnecessary.
1.You needn’t ask for permission when camping in____.
A．national parks in England
B．most parts of Scotland
C．crowded lowland Britain
D．most parts of England
2.The author thinks that a good campsite is one_____.
A．with easy access
B．used previously
C．with modern convenience
D．far away from beaches
3.The last paragraph mainly deals with____.
A．protecting animals
B．building a campfire
C．camping in woodland
D．finding a campsite with privacy
4.The passage is manly about____.
A．the protection of campsites
B．the importance of wild camping
C．the human influence on campsites
D．the dos and don’ts of wild camping
Nature is full of color, from rainbows and roses to butterfly wings and peacock tails. Even the fruits and vegetables you eat have different colors: blue blueberries, red strawberries, green broccoli, and orange carrots.
Plant and animals often use color to attract attention. The substances responsible for these colors belong to a class of chemical called antioxidants(抗氧化物). Plants make antioxidant to protect themselves from the sun’s ultraviolet(UV)(紫外线)light.
Ultraviolet light causes chemicals called free radicals(自由基)to form within plant cells. They can destroy parts of plant. Free radicals also have damaging effects on human beings. Some of these effects like wrinkled skin can be seen. The damage is caused by the free radicals attacking cells in our bodies. Certain cancers and heart disease are linked to free radicals.
Our bodies have natural defences for fighting off free radicals. While we are young, our defences are pretty strong. However, they get weaker as we get older. The body’s built-in defences can only go so far without extra help.
The key to fighting free radicals with fruits and vegetables is to mix and match colors. It’s like sunscreen(防晒霜)for the inside of your body. Go for a range of very bright colors. Colorful foods contain hundreds of healthy chemicals not found anywhere else.
Research into how chemicals in blueberries affect the brain’s function in rats suggests that these chemicals may help our own brains work more efficiently.
Don’t just blame the sun. Ultraviolet light isn’t the only source of free radicals. If you breathe polluted air such as smog, automobile exhaust(废气), or wasted gas from a factory, you take in chemicals that also cause such damage. And, the body itself produces free radicals as it processes food.
1.Which of the following not true?
A．Antioxidants are responsible for plant colors
B．Plants use color to attract attention
C．Antioxidants can protect plants from UV light
D．Antioxidants help free radicals to attack plants
2.In which order do the following facts occur?
a Wrinkled skin can be seen
b UV light causes free radicals to form
c Free radicals damage cells in our bodies
d The sun gives out UV light
A．a,b,c,d B．d,b,c,a
C．c,a,d,b D．d,b,a,c
3.We need extra help for fighting off free radicals from fruits and vegetables because ____.
A．our bodies’ defences are not natural
B．we are too young to defend ourselves
C．our defences get weaker as we get older
D．our bodies’ built-in defences can only go away
4.Which of the following can not cause free radicals to form?
A．Colorful food B．UV light from the sun
C．Polluted air D．The body itself
