使人患病的细菌，一般属于（ ）
A：异养寄生
B：异养腐生
C：自养
D：以上都不对
Name
Li Mei
Age
13
Study at
No. 1 Middle School, Class 8, Grade 7
School
not very big, trees, flowers
a school library, a reading room……
Teachers
kind ……
After-school activities
play tennis, swim……
My school
反证法证明：如果实数a、b满足a2+b2=0，那么a=0且b=0．
则这两种物质中（ ）
