At work, Tom and Jack were chatting:
Tom: Jack, I've been attending evening classes for 8 months now and I have a test next month.
Jack: oh!
Tom: For example, do you know who is Thomas Edison?
Jack: No
Tom: He's the inventor of the light bulb; if you take evening classes you would know this.
The next day, the same discussion took place:
Tom: Do you know who Gandhi is?