A:(3,5)
B:(2,-2)
C:(2,7)
D:(4,9)
——What do you want to be when you graduate from middle school?——I want to be _________university student. I'm in great ______ need of knowledge.
设fx为定义在R上的奇函数,当x≥0时,fx=2x+2x+b (b为常数),则f-1=( )
下列几种生物中,具有成形的细胞核的是( )