精选优质文档-倾情为你奉上2018届二轮复习语法并列句和状语从句专题练.单句语法填空1(2017北京卷)_ birds use their feathers for flight, some of their feathers are for other purposes.2(2017北京卷) If you dont understand something, you may research, study, and talk to other people _ you figure it out.3(2016全国卷)Over time，_ the population grew, people began cutting food into small pieces so it would cook more quickly.4(2016北京卷)I really enjoy listening to music _ it helps me relax and takes
