Sentence 1: Henry noticed that his pond was very messy and needed to be cleaned. 
 Sentence 3: While swimming out in the pond, Henry felt a tug on his leg 
 Sentence 4:  He looked down and saw that his leg was caught on a plant 
 Sentence 5:  He struggled for a long time, but finally got free and swam away 
 Given Sentence 2: He jumped in and began to retrieve sticks and plants from the water.