2级

单选题With the development of industry, the problem of pollution was __________from the very beginning, but no one cared about it until the late 1800s.

参考答案:C进入在线模考
[分析]结构识别
此处考生需鉴别此句是系表结构、被动语态还是过去进行时的用法;此旬意为:随着工业的发展,污染的问题从一开始就显现了;但是直到l9世纪末才有人开始关注它。因此答案为C。