Every Monday morning students in our school would stand at attention watching the nation

问题补充：

Every Monday morning, students in our school would stand at attention, watching the national flag .

A. raising

B. rising

C. being risen

D. being raised

答案：

A. raising

B. rising

C. being risen

D. being raised

解析：考查非谓语动词。“升旗”raise a flag，旗帜是被升起所以用现在分词的被动式。句意为：每天早晨我们学校的学生立正看国旗升起。