填空题
填空题 The topic of this talk is ______.
填空题 Busy families like to buy plastic bags because they can ______.
填空题 While going grocery shopping, the speaker suggests people should take to grocery store ______.
填空题 As a great amount of paper is consumed at work and school, the speaker calls on people to ______.
填空题 What's the final proposal put forward by the speaker?