Sentence 1: Timmy found an old boat with water pooled in the bottom. 
 Sentence 3: Timmy told his pals about his find 
 Sentence 4:  When they went to see the boat, the tadpoles were gone 
 Sentence 5:  Then, they noticed tiny frogs hopping in the grass by the boat 
 Given Sentence 2: He saw tadpoles swimming in the boat.