leave it在这里的意思的“放着不要动”，“不准动它”的意思，用作祈使句有命令的意味

狗狗科普：

The Golden Retriever is a medium-sized breed of dog. They were historically developed as gundogs to retrieve shot waterfowl such as ducks and upland game birds during hunting and shooting parties. As such, they were bred to have a soft mouth to retrieve game undamaged and have an instinctive love of water. The golden retriever has a dense inner coat that provides it with adequate warmth. The outer coat is sleek and water repellent, and lies flat against the body. The official colour of the breed is the varying shades of gold that are most often seen. The breed's intelligence and versatility suit the dogs well for a variety of roles including guide dog for the blind, hearing dog for deaf people, hunting dog, illegal drug detector, and search and rescue participant. Because of their loyal and gentle temperament, golden retrievers are also popular family pets.

金毛寻回犬为中型犬的一种。最早它们是猎犬，用来帮助猎人猎取水禽水鸟。金毛也因此酷爱戏水。金毛毛发茂盛，可以保证其温暖。毛发平滑防水，顺贴身体。金毛的颜色一般是金色。金毛的智力在狗狗中名列前茅，因此常被用做导盲犬、猎犬，以及缉毒犬。由于金毛性格温和乖巧，它也是十分受欢迎的家养宠物。