How do I delete rows in a data frame?

I have a data frame named “mydata” that looks like this this:

   A  B  C   D 
1. 5  4  4   4 
2. 5  4  4   4 
3. 5  4  4   4 
4. 5  4  4   4 
5. 5  4  4   4 
6. 5  4  4   4 
7. 5  4  4   4

I’d like to delete row 2,4,6. For example, like this:

   A  B  C   D
1. 5  4  4  4 
3. 5  4  4  4 
5. 5  4  4  4 
7. 5  4  4  4