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leaves, spring, seen, wet, come, think, were used to

March is a great time to enjoy the unusual flowers of the butterbur（蜂斗菜）. This plant is （1） across most of the UK and it likes （2） places near rivers. Some people （3） that butterbur is like a toilet brush. When the flowers open, they have white on them. Then the heart-shaped （4） appear and they are huge, reaching up to one meter across. In the past, the butterbur had many uses. Its cool leaves （5） treat headaches.