Lesson 7 Disappering islands Minjun: It's so hot today. Jenny: You're telling me. I can't believe it's September. Minjun: Each year, it gets hotter and hotter. Jenny: Yeah. Global warming is a big problem. Minjun: I know. Did you here about the polar bears? Jenny: No. What about them? Minjun: They are losing their homes. Jenny: Why are they losing their homes? Minjun: Because the ice is melting..