Use this A2-B1 ESL science reading passage to learn why dogs wag their tails. It includes key vocabulary, reading comprehension questions, and answers for English learners.Reading LevelA2-B1Word Count286 wordsReading PassageMany people think a wagging tail always means a dog is happy. Sometimes that is true. But dogs wag their tails for many reasons.A dog's tail is part of its body language. Dog..