人教版高中英语选择性必修第四册Unit3 Sea Exploration Period 3 课件

介绍讨论的主题(开头句)：
1.We had a discussion about whether it is necessary to...
2.We’ve had a survey on...
3.I’m writing to tell you about a discussion we have had about...
过渡句：
1.Opinions are divided on this issue.
2.Opinions are mainly divided into two groups.
3.Different people，however，have different opinions/think quite differently on this matter.
介绍正方观点：
1.45% of the students hold the view that...For one thing，...For another thing，...
2.60% of the students are for the idea.
介绍反方观点：
On the contrary/However/As the old saying goes，each coin has two sides.Nearly half of the students think that...On one hand，...on the other hand，...
当前，随着陆地资源短缺、人口膨胀、环境恶化等问题的日益严峻，各沿海国家纷纷把目光投向海洋，加快了对海洋的探索研究和开发利用。一场以开发海洋为标志的“蓝色革命”正在世界范围内兴起。海洋资源的开发利用，在很大程度上推动了经济的发展，满足了人类向海洋要效益的愿望，但在海洋开发探索迅速升温的同时，海洋资源也正承受着前所未有的压力。