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。
While John Gilbert was in hospital, he asked his doctor to tell him whether his operation had been successful,
当约翰。吉尔伯特住院的时候,他问医生他的手术是否成功,