Bill and Bob were sitting outside a clinic. Bill was crying loudly.
"Why are you crying?" Bob asked.
"I came for a blood test," sobbed Bill.
"So? Are you afraid?"
"No. For the blood test, they cut my finger."
Hearing this, Bob immediately began crying profusely.
Astonished, Bill stopped his tears and asked, "Why are you crying now?"
To which Bob replied, "I came for a urine test!"