流经生态系统的总能量是指[ ]

A．照射到该生态系统的全部太阳能

B．照射到该生态系统所有植物体上的全部太阳能

C．该生态系统生产者所固定的全部太阳能

D．生产者传递给消费者的全部太阳能

The students in the class were _____ four groups before they started the game. [ ]

A. divided into

B. separated into

C. divided from

D. separated into