The way we cook is important. In many countries, the two sources of heat used for cooking are natural gas or electric stoves. The World Health Organization(WHO) warns that millions of people are dying every year from indoor air pollution. The WHO finds that poor cooking, heating and lighting technologies are killing millions of people each year.
Indoor air pollution results from the use of dangerous fuels and cook stoves in the home. WHO officials say nearly three billion people are unable to use clean fuels and technologies for cooking, heating and lighting. And they say more than seven million people die from exposure to indoor or outdoor air pollution each year. Of that number, the WHO says about 4.3 million people die from household air pollution given off  by simple biomass(生物燃料）and coal stoves.
These findings show that the home use of poisonous fuels is to blame for many of these deaths. These fuels include wood, coal, animal waste and so on. Carlos Dora is Coordinator in the WHO’ s Department of Public Health, Environmental and Social Determinants of Health. He says people should not use unprocessed coal and kerosene(煤油）fuel indoors. He says opening a window or door to let out the harmful air will not correct the situation. It will only pollute the outdoors. “New technologies and clean fuels can rid people of this problem.”
The United Nations found that more than 95 percent of families in sub-Saharan Africa depend on solid fuels for cooking. It says huge populations in India, China and Latin American countries, such as Guatemala and Peru, are also at risk.
Nigel Bruce is a professor of Public Health at the University of Liverpool. He says researchers are developing good stoves and other equipment to burn fuels in a more efficient way.“There are already many technologies for clean fuels available now. An effective and reasonably low-cost ethanol(酒精）stove that is made by Dometic (a Sweden-based company)is now being tested out. Another interesting development is electric induction stoves.” In India, you can buy an induction stove for about $8. And in Africa you can buy a solar lamp for less than $1.
How is Paragraph 2 mainly developed?

A．By making classifications.	B．By listing numbers.
C．By following time order.	D．By describing a process.

According to Carlos Dora, what is the best solution to indoor air pollution?

A．People should use an effective air cleaner.

B．People should use new technologies and clean fuels.

C．People should open a window or door to let out the harmful air.

D．People should prevent themselves from being exposed to harmful air..

What can we learn from the passage?

A．Most of the deaths from indoor pollution are in developing countries.

B．Burning solid fuels can help limit indoor air pollution .

C．People can buy ethanol stoves made by Dometic in India.

D．There are already two technologies for clean fuels available for use.

Which would be the best title for the passage?

A．The way we cook is changing.

B．Cause of indoor air pollution.

C．The development of electric stoves.

D．Indoor air pollution kills millions each year.