合并同类项:2x-x2y+3x2y-x-4.
原式=2x-x+3x2y-x2y-4
=x+2x2y-4.
The green skirt was _______ the red one so she decided to buy both of them.
A.so beautiful as
B.as beautiful as
C.as more beautiful as
D.so more beautiful as
其诊断为
A.癥瘕
B.妇人瘕聚
C.痛经
D.陈旧性宫外孕
E.妇人腹痛