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。
If a shop assistant told him she had not heard of it, he would pretend to be considerably put out.
要是女售货员告诉他从未听说过这些东西,他会装出十分遗憾和不安的样子。