如果房间缺乏空气，可以用英语表示为 "the room lacks air" 或者 "there is not enough air in the room"。

这个表达方式来源于英语中 "lack" 和 "enough" 这两个单词的含义。"Lack" 意思是 "缺少，不足"，"enough" 意思是 "足够的"。所以 "the room lacks air" 就是指房间里缺少空气，"there is not enough air in the room" 就是指房间里的空气不够。

下面是一些例句：

I can't breathe in this room, it lacks air. (我在这个房间里呼吸不到气，因为缺乏空气。)
The room is stuffy and there is not enough air. (房间闷热，空气不够。)
I need to open a window, the air in the room is stagnant. (我需要打开窗户，因为房间里的空气停滞。)