A:including
B:included
C:include
D:to be included
一年前她有过一场病,从那以后她经常背疼。
(1x2-2x-1x2-4x+4) ÷ 2x2-2x ,其中x=2(tan45°-cos30°).
长江沿江地带的东、西起点分别是( )