鸟类的受精卵在雌鸟体内已经开始进行________发育。卵产出后外界温度低于鸟类体温，就停止发育。
胚胎
地方环境质量标准由（）制订。
A、国务院环境保护委员会
B、省级环境保护专门机构
C、国家环保局
D、省级人民政府
For a moment nothing happened, and then ______ all shouting together.
A．voices had come
B．came voices
C．voices would come
D．did voices come
