A man who has sterile disease goes to the hospital for check-up.
A female doctor gives him a small glass pot, asks him to put some specimens in the pot at home and then bring it back to her.
On the next day, the man returns but the doctor found the glass pot still empty.
"What happened?" she asks.
"Yesterday," he explains, "I tried it with my right hand for a long time, but there was no reaction. Then, I tried it with my left hand, it was still not up! I even asked my wife to help me. She tried it with both hands, it still didn't work. So I asked her to do it with her mouth... but still failed! she couldn't make it up in any way!"
"Stop! Stop!" the doctor raises her voice.
"Fine," he sighs, "but doc, maybe you can help me out on this..."
She can't bear with it anymore, so she shouts, "What!? What do you want me to do!? Huh!"
"Well, let's see if you can make the lid of the glass pot pop up..."