An introductory sentence for a brief summary of the passage is given below. Complete the summary by adding the THREE answer choices that express the most important ideas in the passage. Some answer choices do not belong in the summary because they express ideas that are not given in the passage or are minor ideas in the passage. This question is worth 2 points. A series of reefs composed of small animals called coral, the Great Barrier Reef is extremely old and extremely big. ____________ ____________ ____________ Answer Choices 1. There are many types of coral, several hundred of which exist as part of the Reef, making it one of the most ecologically diverse places on Earth. 2. The Reef is a scientific treasure valued both for what it can contribute to our theoretical understanding of ocean ecology and for what it can yield in terms of compounds used for creating new medicines. 3. Despite efforts to protect large areas of the Reef, the Reef is still threatened by overfishing, shipping accidents, and oil spills. 4. The tourist industry also poses a threat to the Reef, since groups of divers visit it on boats that can cause just as much damage to the coral as shipping vessels if they hit it. 5. The most recent threat to the Reef comes from global warming, since the rising temperature of the ocean water disrupts the corals symbiotic relationship with a type of algae, causing the coral to turn white and die. 6. Coral is quite colorful, coming in an array of reds and blues, all generated and maintained by the presence of different varieties of zooxanthellae within the coral. According to paragraph 1, where does the clipper get its name from?