单项选择题 21()
单项选择题 22()
单项选择题 23()
单项选择题 What does the speaker suggest people should do when they go shopping
单项选择题 How many solar heat panels do three or four bedroom homes usually need
填空题 What forms flood plain
单项选择题 What can we do to avoid the waste of paper
填空题 What does "runoff" mean
单项选择题 What is the purpose of building new houses facing north or south
单项选择题 What’s the problem with paper napkins and plastic food wraps
单项选择题 Which is not true about solar heat collector panels
填空题 What is the passage mainly about
单项选择题 Why is insulation required in new houses
单项选择题 What’ s the talk mainly about
填空题 What characteristics can be of a flood
单项选择题 What do we learn about the use of solar energy in the USA
单项选择题 What is the main topic of the lecture
填空题 How much of all precipitation is runoff
填空题 Legislators have made ______ the basis of many noise reducing programs.
填空题 Noise can produce serious ______ stress.