2018年12月六级 第1套 Section A 选词填空

Just off the coast of Southern California sits Santa Cruz Island, where a magical creature called the island fox __26__. A decade ago, this island's ecosystem was in __27__. Wild pigs attracted golden eagles from the mainland, and those flying __28__ crashed the fox population. So the Nature Conservancy launched a __29__ war against the pigs, complete with helicopters and sharp shooters.

And it worked. Today, federal agencies are pulling the island fox from the Endangered Species List. It's the fastest-ever recovery of a mammal, joining peers like the Louisiana black bear as glowing successes in the history of the Endangered Species Act.

But the recovery of Santa Cruz Island isn't just about the fox. The Nature Conservancy has __30__ war on a multitude of invasive species here, from sheep to plants to the __31__ Argentine ant. "Our philosophy with the island has always been, 'OK, __32__ the threats and let the island go back to what it was,'" says ecologist Christina Boser. And it appears to be working. Native plants are coming back, and the fox once again bounds about carefree.

But keeping those foxes from harm will occupy Boser and her colleagues for years to come. You see, humans are still allowed on Santa Cruz Island, and they bring dogs. So Boser has to vaccinate her foxes against various diseases. "We're obligated to keep a pulse on the population for at least five years after the foxes are delisted," says Boser. That includes tagging the foxes and __33__ their numbers to ensure nothing goes wrong.

This is the story of the little fox that has come back, and the people who have __34__ their lives to protect it. This is the story of wildlife conservation in the age of mass __35__.