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。
They took with them dogs, rats and plants like the sweet potato,and settled mainly in North Island where the weather was warmer.
他们随身带去了狗、老鼠及像红薯之类的植物,并且大部分定居在气候比较温暖的北岛。