Professor Jordon is well known for his into the habits of the mon housefly.
A. examination
B. introduction
C. research
D. expression
网友回答
A. examination
B. introduction
(答案→)C. research
D. expression
解析：research into对...研究：1)(作动词用)He is researching into the reading problems of young school children.2)（作名词用）to carry out a research(=some research)into the causes of brain damage.(对大脑损伤原因进行研究)。
研究可译为make researches into, make a study of 或直接用动词study vt或research into (a problem etc.).