All I could mumble in response was that when I was a man of fifty, my mother would lean out of the window when I left and remind me not to drive too fast.
Please don't mumble.
"Oh? Then, as I expected, I've been around longer than you. This year I'm 20-mumble years old." "What does that tell me?"
I heard him mumble to himself.
"Hrmm," mumbled Professor Takeda as he twisted his moustache.