When the Professor turns on the blender, he didn't put the lid on, but the drink didn't explode. On tons of shows, the stuff in blenders explodes, so how come nothing happened here.
(Trying to sing the National Anthem)
Goofy: Oh, the national anthem goes like this, do da. Do da. The national anthem goes like this. All the doo-dum day.
Mike: The National Anthem does NOT go like that, Goofy.
Mike the Microphone: And now, the home-run king of cartoon comedy: Mickey Mouse!
Goofy: Hey, Ump! What kind of call was that? You lazy no good (air-horn blast)! I oughta come down there and (2 air-horn blasts)! And I've got 4 words for you, Gracie: (4 air-horn blasts)!