In 1957, English scientist James Lovelock invented the Electron Capture Detector, an inexpensive, sensitive device used to help measure the spread of poisonous man-made compounds (化合物) in the environment. The device provided the scientific foundations of Rachel Carson’s 1962 book, Silent Spring, a push for the environmental movement. It also helped provide the basis for regulations in the United States and in other nations that banned harmful chemicals like DDT and PCBs.
Later, his discovery that chlorofluorocarbons(CFCs)—compounds that are used in refrigerators and air conditioners—were present in measurable concentrations in the atmosphere led to the discovery of a hole in the ozone layer (臭氧层). He also explained that they posed no possible danger to the planet. A year after his paper in Nature, Mario Molina of the Massachusetts Institute of Technology and F. Sherwood Rowland of the University of California at Irvine published a paper in the same journal detailing how sensitive the Earth’s ozone layer is to CFCs. In 1995 they were awarded the Nobel Prize for their work in reminding the world of the thinning of the ozone layer. Lovelock later called his conclusion a mistake.
But Dr Lovelock may be most widely known for his Gaia theory that the Earth acts as a “living organism” that can “control its temperature and chemistry in a state of comfortable stability (稳定性).” As an expert on the chemical composition of the atmospheres of Earth and Mars, Dr Lovelock wondered why Earth’s atmosphere was so stable. He hypothesized (假定)that something must control heat, oxygen, nitrogen, and other ingredients. He presented his theory in 1967. That summer, the novelist William Golding, his friend, suggested the name Gaia, after the Greek goddess of the Earth.
The hypothesis may never have moved into the scientific mainstream without the contribution of Lynn Margulis, an American microbiologist. In the early 1970s and in the decades that followed, she worked with Dr Lovelock on specific studies to support this concept. Since then. Dr Lovelock’s theory of a self-controlling Earth has been considered important to understanding the causes and consequences of global warming.
【小题1】What is Paragraph 1 mainly about?| A．The functions of man-made compounds. |
| B．The importance of banning harmful chemicals. |
| C．The influence of the Electron Capture Detector. |
| D．The working principles of the Electron Capture Detector. |
| A．It was impossible to find CFCs in thin air. |
| B．CFCs did little harm to the Earth. |
| C．It was impossible to measure CFCs in the air. |
| D．CFCs had little effect on cooling refrigerators. |
| A．Earth’s atmosphere remains stable. |
| B．Golding mentioned a Greek goddess. |
| C．Both Earth and Mars have atmospheres. |
| D．Living things can exist in the atmosphere. |
| A．She became well-known because of Lovelock. |
| B．She first discovered the causes of global warming. |
| C．She helped Lovelock make his theory widely accepted. |
| D．She proposed a new idea based on Lovelock’s Gaia theory. |
