contents
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topic 1: classification of living organisms ������|1
topic 2: photosynthesis �������|6
topic 3: trees ��ľ|9
topic 4: rain forest ����|13
topic 5: redwood �tɼ|16
topic 6: fall colors ��ɫ|20
topic 7: life cycle of flowering plants �_��ֲ�����������|23 topic 8: animal kingdom ��������|26
topic 9: animal thermoregulation ����Ĝض��{��|30
topic 10: life cycle of frogs ���ܵ���������|33
topic 11: the ant colony ρȺ|36
topic 12: ants�� life cycle Λρ����������|38
topic 13: life cycle of worker bees �������������|41
topic 14: honey bee colony ��Ⱥ|43
topic 15: life cycle of a butterfly ��������������|46
topic 16: leafcutter ants ���~ρ|49
topic 17: life cycle of pacific salmon �q�~����������|52
topic 18: how elephants cope with heat �����������|56
topic 19: how penguins cope with cold ���Z�������|59
topic 20: animal migration �����w��|63
topic 21: bat and echolocation �����•��λ|67
topic 22: honey bee dancing �۷����|69
topic 23: monarch butterfly migration �������w��|72
topic 24: ecosystem ���Bϵ�y|75
topic 25: carbon cycle ̼ѭ�h|78
topic 26: energy transfer in ecosystems ���Bϵ�y��������|80
topic 27: coral reef ɺ����|85
keyword list ���~��|89
bank of expressions ���_��|102
references �����īI|112