"They have a cold" 是指他们感冒了的英文表达方式。

来源：“cold”是一种常见的呼吸道感染，通常由冷空气、湿环境、缺乏睡眠和免疫力低下等因素导致。

例句：

"I think John has a cold, he's been coughing all day."
(我认为John感冒了，他整天都在咳嗽。)
"My daughter caught a cold at school, she's been feepng under the weather for a few days now."
(我的女儿在学校感冒了，她现在已经有几天感觉不适了。)

注意：在日常对话中，人们常常简单地说“I have a cold”或“She has a cold”表示自己或他人感冒了。