I am writing to express my for the safety of children travelling on school buses, especially those on high-risk and highway-speed routes.
A. attention
B. emotion
C. affair
D. concern
网友回答
A. attention
B. emotion
C. affair
(答案→)D. concern
解析：名词辨析。A关注；B情感；情绪；C事务；D关心，担心；句意：我在写信表达我对孩子的安全地担心。故D正确。