"eating lunch" 可以独立造句。例如：

1. She is eating lunch now.

2. I am eating lunch now.

3. They are eating lunch together.

需要注意的是，虽然 "eating lunch" 可以独立造句，但在正式场合或需要更明确表达时，使用 "have lunch" 更为常见和恰当。例如：

1. She is having lunch.

2. I have lunch at noon.

此外，"eating lunch" 通常用于描述正在进行的动作，而 "have lunch" 则更常用于表示习惯性或一般性的行为。