It took a long time for the connection between body temperature and illness .
A. to make
B. to be made
C. making
D. being made
网友回答
A. to make
(答案→)B. to be made
C. making
D. being made
解析：根据句型It takes some time to do sth.可排除C和D项。由因为the connection between body temperature and illness和make之间为被动关系，故选B项。