一、1、cover2、waste3、undertake4、move二、1、gases指不同种类2、stream3、value三、1、The water is necessary for the flowers2、The window is tried to clean up by the boys(我实在想不到别的，只好改成被动式）3、Climbing the mountain is easy for me...
1. cover
waste follow travel 2. gases streams valuable 3. The flowers will die if there is no water .The boy do their best to clean the window .It is easy eno...
一.1.cover2.waste3.obey4.travel二.1.gases2.streams3.valuable三.1.The flowers will die if there is no water2.The boy try to make the window clean3.To climb the ...
