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"，而 "be on one's own" 意为 "独自"。根据题意，警察要求学生在上学的路上保持警惕，因此正确答案是 "guard"。