Americans smoke six thousand million cigarettes (香烟) every year, that is, every person smokes about 4195 cigarettes a year in the country of 18 years of age or more. It has been calculated (测算) that 51% of American men smoke while 34% of American women do so.

　　Since 1930, scientific studies have shown time and again that smoking does great harm to one' s health and that it will shorten one's life.

　　Cigarette smoking is believed, to most research workers in this field, a very important cause in the development of cancer (癌症) of the lungs and the cancer of the throat and is believed to have much to do with some other kinds of cancers. Cigarette smokers suffer from the illness of the heart more often than those who don't smoke. But strange, yet true, women are thought to be less affected (影响) , because when women smoke, they usually don' t breathe in the smoke so deeply. Most of the doctors and researchers say, “Give up smoking. If you don't smoke－don't start!”

　　Filters (过滤嘴) are required now to make smoking a bit safer, but they can only reduce, not get rid of, its poison.

　　But there are still a number of doctors and research workers who are less sure of the effect (影响) of cigarette smoking on health. They believe that cancers of the lungs, the throat and so on may also be caused by atmospheric pollution, or chemical poison that is now being used by farmers in large quantities to destroy plant pests (害虫) and small animals.

1． ________each smoke about 4195 cigarettes a year.

[　　]

2．It is believed by many that cancers of the lungs and throat are caused ________ by smoking.

[　　]

3．Smoking has much to do with ________.

[　　]

4．Doctors and research workers advise that ________.

[　　]

A．we should smoke filter-tipped cigarettes

B．we must not breathe in the smoke deeply when smoking

C．those who don't smoke shouldn't start

D．those who smoke less

5．From the passage we come to know that people may die from ________.

[　　]

I tried your cigarette ________.

1. A.
   once and twice
2. B.
   one and two
3. C.
   once or twice
4. D.
   one and twice

You must______your cigarette when you are at the gas station.