[单项选择]Concrete is probably used more widely than any other substance except water, yet it remains largely unappreciated. "Some people view the 20th century as the atomic age, the space age, the computer age—but an argument can be made that it was the concrete age," says cement specialist Hendrik van Oss. "It’s a miracle material. " Indeed, more than a ton of concrete is produced each year for every man, woman and child on Earth. Yet concrete is generally ignored outside the engineering world, a victim of its own ubiquity and the industry’s conservative pace of development. Now, thanks to environmental pressures and entrepreneurial innovation, a new generation of concretes is emerging. This high-tech assortment of concrete confections promises to be stronger, lighter, and more environmentally friendly than ever before.
The concretes they will replace are, for the most part, strong and durable, but with limitations. Concrete is sound under compression but weak under tension. Steel rebar
A. Concrete suffers from its own unique features as well as the slow development of building industry.
B. Concrete is not appreciated because of its dull color, its drawbacks, with little improvement as a building material.
C. Slow progress of building industry does harm to the application and popularity of concrete.
D. Concrete is ignored because it is too common with little advance in its technology.