_______ hamburgers are junk food, many children like them.

A．If         B．Unless             C．Because                 D．Although

_______ hamburgers are junk food, many children like them.

A．If          B．Unless            C．Because             D．Although

_______ hamburgers are junk food, many children like them.

A．If         B．Unless             C．Because                    D．Although

_______ hamburgers are junk food, many children like them.

A．If         B．Unless         C．Because           D．Although

No air means death．Although we cannot see it, there is air around us．So air is everything, and it gives life to every living thing．Bad air makes people ill．We must have fresh air to keep us healthy．

In the city there are a great many people and there are too many cars running on the roads．The gas which the cars spread (扩散) out is full of poison(毒物)．Every day we breathe it in again and again．This makes us feel sick．Besides so many cars, there are many factories too．From the chimneys of these factories, we get the smoke usually in black and grey color．This kind of the smoke, when it mixes the air, is dangerous to our health, it is because smoke contains (包含) many poisonous solid and gases．So in order to keep us healthy we have to go out to the countryside to breathe more fresh air．Or we can go up hills to get more fresh air．

1．Which of the following best explains that no air means death?

A．Bad air makes people sick．                B．Air can't be seen anywhere around us．

C．Air gives life to every living thing．           D．Fresh air keeps people healthy．

2．Where do people usually breathe fresh air?

A．In big cities．                           B．On the roads．

C．In the countryside．                     D．Around factories．

3．Smoke from the chimneys is dangerous to our health

A．when it makes air dirty                   B．if it contains poisonous solids and gases

C．no matter how it spreads out             D．because it is in black and grey color

4．According to the passage, we know that                        ．

A．we shouldn't go out of doors as much as possible

B．smoke from chimneys is more serious than gas from the cars

C．a great many people have to breathe air in again and again

D．going up hills is one of the best ways to keep healthy

5．The best title for the passage is            ．

      A．The Use of Air        B．Breathing Air           C．Fresh Air                D．Bad Air