Unit 12 FireLead-inthe Torch Festival 火把节Make a fire to cook生火做饭fire disaster火灾New wordsfire火；火灾hurt（使）受伤must必须careful小心的smoke吸烟hate讨厌Listen and sayWe must be careful with fire. We mustn’t play with matches.Fire can burn down a lot of trees. It can hurt people too. We must be careful with fire.1Children, what do you know about fire safety? What mustn’t we do in the forest or at home? We mustn’t smoke in the forest. We mustn’t play with matches at home. We mustn’t play near fires at home. Very good. Safety first.2Look, ask and answer.Fire safetyIn the forestAt home smoke play with matches play near fires What mustn’t we do…?We mustn’t…Play rolesWe mustn’t smoke in the forest.What mustn’t we do in the forest?We mustn’t play with matches at home. What mustn’t we do at home?We mustn’t play play near fires at home.What mustn’t we do at home?Language points1. We must be careful with fire. 我们必须当心火。 must 表示主观的必要，语气主动、强烈，意思是“必须”，它是情态动词。情态动词不能单独作谓语，只能与行为动词的原形一起构成谓语。 must 的用法如下：(1) 表示主观的必要，意为“必须”。 例句： You must do your homework today. 你今天必须做家庭作业。(2) 表示语气肯定的猜测，意思是“一定”，用于肯定句中。 例句： He must be a doctor. 他一定是一名医生。 must not (mustn’t) 表示“禁止；不允许”。 例句： You mustn’t swim in the river. It is dangerous! 你禁止在河里游泳。危险！ (3) 由 must 引导的一般疑问句，肯定回答用 must 或have to ，否定回答用 needn’t 或 don’t have to. 例句：— Must I go out? 我必须出去吗？ —No, you needn’t/don’t have to. 不，没有必要。Look and learnDon’t smoke!Don’t play with matches!不要吸烟！不要玩火柴！Language points2. Don’t smoke! 不要吸烟！ 这是一个否定的祈使句。其句型结构为“ Don’t + ...
