6 . In the ground below a tall New York City apartment building, several machines collect carbon dioxide(CO₂)from large gas-powered boilers which help heat the building but also release CO₂ into the atmosphere.

Nearly 70 percent of New York City’s large buildings have steam boilers that run on natural gas or oil. Big buildings in New York City release about two-thirds of the city’s emissions(排放). New York state’s buildings also release more air pollution than any other state.

Brian Asparro, chief operating officer of CarbonQuest—the company that built the machines to capture(捕获)the CO₂ in the apartment buildings—said, “Time is not on our side, and this type of solution can be cost-effective and without a major destruction.”

The machines cool the CO₂ to about-23℃. At that temperature, the gas becomes liquid and can be carried away by trucks to Brooklyn, another area in New York City. There, another company turns the liquid into a solid, The solid CO₂ then reacts with calcium to form calcium carbonate(碳酸钙), which goes into concrete, Once the CO₂ is in concrete, ‘it will not release into the atmosphere unless the concrete is heated to about 600℃.

However, critics say, “Carbon capture doesn’t actually reduce emissions; it seeks to put them somewhere else.” Critics also worry that it is dangerous to keep large amounts of CO₂ below buildings. If too much of the gas is released by accident, it could cause health problems and even death.

But supporters of capturing the CO₂ say it is safe. They also argue that boilers and other gas heating systems are probably more dangerous than the machines that capture the CO₂.

Under a new state law in New York, many buildings must reduce their emissions. If they do not lower their emissions, the building owners will have to pay a fine. What’s more, to help increase the use of carbon capture machines, the government lowers taxes for owners who put them in their buildings.

1. How do carbon capture machines in New York City work?

A．By heating the carbon dioxide to 600℃.

B．By changing the physical state of carbon dioxide.

C．By replacing large gas-powered boilers gradually.

D．By transporting the carbon dioxide to other cities.

2. What are critics worried about concerning carbon capture machines?

A．Their cost.	B．Their occupied area.
C．Their safety.	D．Their harm to the environment.

3. What is the government’s attitude to the carbon capture machines?

A．Supportive.

B．Doubtful.

C．Unclear.

D．Unconcerned.

4. What is the best title for the text?

A．A Major Crisis of Environmental Pollution

B．A Disadvantage of Carbon Capture and Storage

C．The Development of a Company Called CarbonQuest

D．Carbon Capture Technology for Tall Buildings in New York City