A woman went to a grocery store..

She gets a shopping cart and went to buy the stuff she needs.
First, she bought a tray of eggs.
Next, 3 bottles of milk.
And last, lettuce.

Now that she's done, she went to the cashier and puts her groceries on the conveyer belt.
The clerk, saw the stuff she bought.
He noticed the tray of eggs, the bottles of milk, and the lettuce.
The clerk told the woman, "You must be single."
And the woman, was so shocked and surprised on what the clerk said, "Yes, I am single! How do you know?" asked the woman with a shocked expression.
And the clerk responded, "Because you're ugly."