Next put all the ingredients in a big bowl and ________.
A:mix up them
B:mix them up
C:mix it up
D:mix up it
工厂中,贾师傅每天生产10个零件,李师傅每天生产20零件,现需要300个零件。若全由贾师傅生产,a天后可以完成,列出等量关系式为____。
I'm not ____ whether Dad will drive me to school or not.
根瘤菌与大豆的根共生,根瘤菌的作用是( )