单项选择题

Over the past two decades gee—engineering began to include other ways of fixing climate-including new spins on the Pinatubo effect. Using sulfur dioxide(二氧化硫) or other materials, they aim to reflect sunlight back into outer space. One would boost a series of mirrors into orbit, shading Earth from sunlight, but at a cost that would likely bankrupt the planet. In the 1990s, the controversial inventor of the hydrogen bomb, Edward Teller, proposed floating reflective particles of metal in the atmosphere, adding a Dr. Strangelove air to the gee-engineering field.
Various kinds of materials are used in gee-engineering to