题目
The police asked students to always be on their ____ when walking to school.A. guardB. attentionC. own
The police asked students to always be on their ____ when walking to school.
A. guard
B. attention
C. own
题目解答
答案
A. guard
解析
此题考查的是固定搭配。短语 "be on one's guard" 意为 "保持警惕"，符合题意。其他选项 "be on one's attention" 和 "be on one's own" 不是正确的搭配。