听力原文： Welcome to Emmerson National Park. I'm Dean and this is Dan and we'll be your guides today on what is sure to be a wonderful experience. We are delighted to be assisting you in experiencing the flora that is unique to Emmerson National Park. Following the tour of the park, we'll be having lunch at the Atrium located in the visitors' center. The spring season has fully arrived so you will be able to see that everything is in full bloom. Some of our species of plants do not exist in any other country in the world, so have your cameras ready, but please do not touch any of the plants. It's also important to remember that littering of any sort is strictly prohibited. Please put all of your trash into the garbage canisters provided in the park. Who is the speaker?