Every had been made in order to save the boy with the H5N1 bird flu, but all in vain. He died at last.
A. effect
B. affect
C. infect
D. effort
网友回答
A. effect
B. affect
C. infect
(答案→)D. effort
解析：词义辨析。A.影响 B. 情感 C.感染 D. 努力。句意：为了救助感染H5N1禽流感的男孩，付出了所有努力，但是都无济于事。他最后死了。故选D。