时间:2021-01-06 16:45 来源：陕西成考网 点击: 206 次
If you are writing or studyin9，it makes very much difference where the light comes from.People who use books and pens every day have to be especially careful about the way the light shines on their work.
Every house gets i ts light either from daylight through the windows--which is the very best to use--or from lamps or electricity：but whichever kind of light it is，the way it shines toward our book or work is a matter of great importance to the eyes.
Take a book.sit with your back toward the window，and try to read.Your shadow(影子) falls all over the page and makes it almost as bad for your eyes as if you were in a dark room.
Now turn around and face the window.The page is in the shadow again，while the bright light is in your eyes.
Try sitting with you fight side toward the window.This is very well for reading，but if you were writing.the shadow of your hand would fall across the page and bother(打搅)you a little.
There is just one other way：sit with your left side to the window.Now everything is perfect for reading and for writing，too.
Whatever kind oi light is in the room，the rule about the right to sit is always the same.
第44题 Which of the following is true?
A.How the light shines on our work is of much importance.
B.The way the light shines on your work makes no difference.
C.We needn't care about where the light comes from.
D.People can write or study under a light that comes from any direction.
第45题 You shouldn't sit with your back towards the window because________.
A.the light is too dark
B.the light is bad for your eyes
C.you are in a dark room
D.your book is in your shadow
第46题 When you sit with your face towards the window, ________.
A.your shadow falls on your book
B.your book is in a shadow
C.the light is still dark
D.the light is on your page
第47题 The best way both for reading and for writing is to________.
A.sit facing the light
B.1et the light shine from your back
C.sit with your right side towards the light
D.have the light come from your left
Forty—thousand of the world’ s young children die every day.Many of these deaths can be prevented.In fact，experts say，techniques now exist to save the lives of half of these children.The techniques are medically effective(有效的)，simple to use and low cost.The biggest task has been to inform parents about these life-saving techniques.
Diarrhea(腹泻)is the main cause of death among children in developing countries.Diarrhea results when the body tries to clear itself of harmful bacteria(细菌).The body does this by getting our liquids，sometimes uncontrollably.If too much water，sugar and salt ale lost in this way，the body cannot work normally.The child may die.
The Uni ted Nations International Children’s Fund，UNICF，introduces a technique.It uses a simple mixture of sugar and salt in water.The mixture does not stop diarrhea.But if used often as needed，it keeps fluid(体液)levels normal until the body has fought off the harmful bacteria.
In Egypt，for example，the treatment was used in a children’s health care program in the province of Alexandria.It reduced by one—half the number of deaths caused by diarrhea.The technique has now been used throughout the country.
第48题 According to the passage，a large number of Children can be saved only when________.
A.the life—saving ways are medically effective
B.their parents are rich enough for the life—saving techniques
C.rite life—saving techniques are easy to use
D.their parents learn the life—saving techniques
第49题 Which of the following situations will cause the death of a child?
A.Tile child clears its body of bacteria.
B.The body loses liquids without any control.
C.The child has diarrhea in a developing country.
D.The body controls its fluid levels.
第50题 When the mixture is used，it is important to________..
A.keep sugar and salt in water
B.drink it as often as necessary
C.take it as much as possible
D.use it to kill the bacteria