单项选择题A．Eastern EuropeB．Northern EuropeC．Western EuropeD．Southern Europe

单项选择题A．the demand is too lowB．the supply is too largeC．the cost is too highD．the price is changeable

单项选择题A．nearest of all planets to the sunB．extremely hotC．little known to peopleD．biggest of all planets

填空题highway system

填空题bulk