Throughout seafaring history, ships and sailors have been lost to storms, accidents and war. Until recently, most of these ships were weak wooden sailing vessel (船只), their skeletons(骨架) quickly eaten away by sea creatures. Now, large vessels made of steel float on the seas. Thousands of these huge ships have been lost in times of war and in times of peace. The bones of great metal ships, unlike the wooden vessels of old, survive the destruction of the sea long enough to become home and harbor for underwater life of all kinds. Shipwrecks(残骸) often provide the only hard surface and structure at the sandy bottom of the sea, something many sea creatures need. The ship has been underwater for only five days. Its surface is still clean. Six weeks later, the wreck is covered with a slimy layer of algae(海藻), but it is still recognizable as a ship. Soon, animals that need to attach themselves to a hard surface, like the feather duster worms, make the wreck their home. In warm waters, coral polyps(珊瑚虫) settle on the wreck and begin the process of building a rock-like crust on the ship. Small fish are attracted on all of these creatures. Larger fish come to feed on these small fish that hide in the wreckage. Eventually, the largest animals are attracted to the rich life on the shipwreck. Shipwrecks give us valuable information about how sea plants and animals develop. We know exactly how long this wreck has been under water and how long sea life has been growing on it. Yet even the strongest steel shipwreck will finally be destroyed by the flows of water. But long after this wreck has been broken apart, it will still act as a reef (礁石). Layer upon layer of sea life has formed a structure that is now more natural than artificial, and will remain an island of life under the sea. 小题1:Which of the following is NOT TRUE about shipwrecks?
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