【题目】In salute to our national flag， every citizen must stand while focusing their eyes on the rising flag.
A. at attention B. at random
C. at ease D. at hand
在线课程【答案】A
【解析】
考查动词词组。A. at attention在关注；B. at random随便地；C. at ease舒适地；D. at hand近在手边。句意：在向国旗致敬时，每个公民必须立正，他们的眼睛要关注上升的国旗。故选A。