Two scientists at a restaurant. When the waiter asked the what to drink, the first scientist said, ""I'll have H2O."" The second scientist started to say ""I'll have H20 too,"" but then he told the first scientist, ""Wait a minute. You had something up your sleeves, didn't you?"" He then told the waitress, ""I'll have a glass of water."" The first scientist was furious, staring at him in anger, because his plan to kill the second scientist has failed.