The most serious problem _our teacher is… a.facing to b.facing写原因如题

why air pollution is the most serious? But,if the electricity comes from coal-powered power plants,there are still serious pollution pro cuz you are soul serious most of the time. Air _____ (pollute) is the most serious of all. most serious 造句 The ______________ is one of the most serious problems in most big cities. I think the serious pollution is one of the c_____ for most countries What is the most serious pollution in China?and what is it result from? what do you think is the most serious chanllenge of living in a city like shanghai? What do you think is the most serious challenge of living in a city like Bei What are the most serious social problems China is facing nowin English What do you think is the most serious challenge of living in a city like Guangzhou? A____(三)degree burn is the most serious of all burn types 用英语描述一下地震开头：Earthquakes are one of the most serious natural disasters in the world 我有点对这个句子理解无能.>< The low of books to people is the most serious problem what are you most serious problem will the english lanaguage以这个为题写一篇文章，what are you most serious problem with the english language ······ 英语翻译the pro-technology message . MILK THE COW PRO怎么样