But a study of a food chain in Isle Royal National Park, an island in Lake Superior, has shown that food-chain control can work in both directions.是什么意思_But a study of a food chain in Isle Royal National Park, an island in Lake Superior, has shown that food-chain control can work in both directions.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句