In the late 1970’s,many people in North America turned their attention to environmental problems ，and new steel — and — glass skyscrapers were widely criticized. Some ecologists (生态学家）pointed out that a number of tall buildings in a city often overburden public transportation.
Skyscrapers are also lavish consumers of electric power and water. In just one recent year, the addition of 17 million square feet of skyscraper office space in New York City itself has already raised the top daily demand for electricity by 120, 000 kw — enough to supply the entire city of Albany in New York area for a single day.
Glass—walled skyscrapers can also be especially wasteful. The heat loss ，or gain， through a wall of half 一 inch plate glass is more than ten times that through a typical ordinary wall filled with bricks or board. In order to decrease the pressure on heating and air — conditioning equipment, builders of skyscrapers have begun to use double—layered glass ，and reflective glasses coated with silver or gold mirror films that could reduce glare (强光）as well as heat gain. However, mirror — walled skyscrapers may raise the temperature of the surrounding air and affect neighboring buildings as well.
Skyscrapers put a severe pressure on a city's sanitation (卫生）facilities, too. If fully occupied, the towers just within the central area of New York would alone produce 2. 25 million gallons of waste water each year^—as much as the city size of Stanford， Connecticut, which has a population of more than 109，000.
The underlined phrase“ lavish consumers ”in the 2nd paragraph probably means ____

A．trash producers

B．great spenders

C．pressure makers

D．poor customers

Glass walls of skyscrapers are specially mentioned in order to _____.

A．show how skyscrapers manage to lessen their pressure

B．explain why skyscrapers can control its air conditions

C．describe further how wasteful skyscrapers could be

D．present the stability of skyscrapers in modern buildings

From the last paragraph we can learn that _____.

A．central New York skyscrapers are a large waste water producer

B．the central area of New York is as large as the city of Stanford

C．more than 109，000 people live in the skyscrapers in New York

D．New York produces 2. 25 million gallons of waste water each year

When the writer talks about skyscrapers ，his tone sounds _____

A．positive

B．doubtful

C．grateful

D．negative