题目内容
_____ to sunlight for too much time will do harm to one’s skin.
A．Exposed B．Having exposed C．Being exposed D．to expose
C
【解析】
试题分析：考查动名词短语在句中做主语用法。本题的being exposed to sunlight too much time在句中充当的是主语。句意：过多地暴露在阳光下对人的皮肤是有害的。故C正确。
考点：考查动名词做主语
点评：要注意动名词做主语和不定式做主语之间的差别。动名词做主语表示的是经常性习惯性的行为，不定式做主语表示的是一次性具体的行为。
动词填空：根据句意用所给动词或动词短语的适当形式填空(每小题1分，共10分)
| arrange inform of break down put forward delight concentrate on take up contribute to expose accuse of |
The suggestion ________________ by the chairman was rejected at yesterday’s meeting.
_____________ to sunlight for too much time will do harm to your skin.
Doing sports on a regular basis _____________ our health.
His car __________ constantly ___________, which makes him crazy especially when he is in a hurry.
In order to calm their child down, the mother _____________ the story where the father left off the night before.
______________ to live in the countryside, he has never thought of seeking fortune in the big cities.
He couldn’t ____________________ his experiment with so much noise going on outside the labs.
Being afraid of falling behind the times, he has always been keeping himself ____________ the latest development of technology.
The young man _________________ stealing three times since he left high school.
He demanded that a car _______________ to pick him up at the airport.
Vitamin D helps bones and muscles grow strong and healthy. Low levels of vitamin D can lead to diseases such as rickets (佝偻病), mainly found in children. The thinning of bone is a common problem as people, especially women, get older.
But more and more research is suggesting that vitamin D might also help prevent many diseases. The easiest way to get vitamin D is from sunlight. The sun’s ultraviolet (紫外线的) rays react with skin cells to produce vitamin D. But many people worry about getting skin cancer and skin damage from the sun. As a result they stay out of the sun. Also, darker-skinned people produce less vitamin D than lighter-skinned people. The amount also decreases in older people and those living in northern areas that get less sunlight.
Not many foods naturally contain vitamin D. Foods high in this vitamin include oily fish and fish liveroils (鱼肝油). Farmed fish have only about one-fourth as much vitamin D as wild fish. Small amounts of vitamin D are found in beef liver, cheese and egg yolks. But most of the vitamin D in the American diet comes from foods such as milk.
Research in the last several years has shown that low levels of vitamin D may increase the risk of heart attacks in men and deaths from some cancers. More doctors are now having their patients tested for their vitamin D levels. But as research continues, some experts worry that if people take too much vitamin D, it might act as a poison. Also, skin doctors warn people to be careful with sun exposure because of the risk of skin cancer.
【小题1】The first paragraph is mainly about .
| A．the muscle diseases | B．the sources of vitamins |
| C．the importance of health | D．the functions of vitamin D |
| A．Elderly darker-skinned people. | B．Young lighter-skinned people. |
| C．Elderly lighter-skinned people. | D．Young darker-skinned people. |
| A．beef liver | B．cheese | C．wild fish | D．farmed fish |
A. Being exposed to sunlight is the safest way to get vitamin D.
B. Lack of vitamin D can make people age quickly.
C. Proper vitamin D levels people need are still not determined now.
D. The vitamin D level is higher in men than in women.