(课件网) “课时跟踪检测”见“Unit 3 课时跟踪检测（一）” (单击进入电子文档) 谢 谢 观 看 Unit 3 Under the sea 海洋一一个令人向往而又充满奥秘的地方。美丽的珊瑚、各种各样的鱼类，还有许多未知的 生物，这些都激励着人们去探索、去求知。 sea turtle dolphin shark killer whale It was a time when the killer whales, 定语从句 or“killers”as they were then called, 定语从句 helped the whalers catch the baleen whales that were on their annual migration. 定语从句
