Yesterday afternoon, I ______ basketball with my classmates for two hours.

A．play

B．played

C．have played

D．had played

青蛙个体的发育过程是：受精卵→蝌蚪→蛙。在这复杂的发育过程中，起决定作用的是[ ]

A．细胞分裂

B．细胞生长

C．细胞的分裂和生长

D．细胞分化