求英语高手解答Environmentally friendly tourism has become _________

求英语高手解答
Environmentally friendly tourism has become ______________and people all over the world are interested in natural wonders. For many places, this is good news, but for the Galapagos Islands, it’s not. Large numbers of people go there every year to observe unique animals in their natural _________. Officials _____________strict rules on all incoming ships and planes and _______any animals from the ___________, but some still occasionally get onto the islands. This causes problems. For example, cats and dogs were brought to the island hundreds of years ago and now they attack the local birds