He has come to be recognized as an expert in the problem of overpopulation and food supply.
由于他的经验促使他终于成为了公认的人口过剩和食物供应问题的专家。
The cry had certainly come form one of the chimneys, but as there were so many of them, the fire fighters could not be certain which one it was.
喊叫声肯定是从烟囱里传出来的,然而,因为烟囱太多,消防队员无法确定到底是哪一个。