一、基础用法造句

1. The students waved the national flag during the parade.（学生们在阅兵仪式中挥舞国旗。）

2. The flagpole stands tall in the middle of the square.（旗杆矗立在广场中央。）

二、短语搭配造句

1. The company raised the red flag on its website to warn of system issues.（公司通过网站亮起红色警示旗通知系统故障。）

2. The flag of the United States is represented by 13 stars and 13 stripes.（美国国旗由13颗星和13条条纹组成。）

三、固定表达造句

1. His interest in sports has begun to flag recently.（他最近对体育的兴趣逐渐减弱了。）

2. The company's profits have been on the decline for the last quarter.（公司上个季度利润持续下滑。）

3. The teacher raised the flag to signal the start of the meeting.（老师举旗示意会议开始。）

四、易混淆点辨析

注意"flag"作动词时意为"降旗"，如：The flag was lowered at noon.（中午降旗。）而作名词时则指"旗帜"，如：The flag on the roof is very old.（屋顶的旗帜很旧。）

建议结合具体语境选择造句类型，并注意区分"flag"作不同词性和含义时的用法。