腐生细菌在生态系统中属于（ ）
A．生产者
B．消费者
C．分解者
D．以上都是
答案：C
Don't forget _____ the lights when you leave the classroom. It saves electricity (电).[ ]
A. to turn off
B. turning off
C. to turn on
D. turning on
吹鼻通关散功效与作用
