The H7N9 flu is reported higher fever and coughing for several days.
A. taking the form of
B. to take the form of
C. to be taken the form of
D. having taken the form of
网友回答
A. taking the form of
(答案→)B. to take the form of
C. to be taken the form of
D. having taken the form of
解析：句意: 据报道H7N9病毒的症状是连续几天的高烧和咳嗽。sth be reported to do sth据报道，这是固定句型，这里take the form of与the H7N9 flu之间是主动关系，故选B。