I am writing to express my for the safety of children travelling on school buses especia

问题补充：

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

答案：

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。