1: What do these mean: C-h, M-C-a, RET, "ESC a", etc.? C-x: press the `x' key while holding down the Control key M-x: press the `x' key while holding down the Meta key (if your computer doesn't have a Meta key, see question 125) M-C-x: press the `x' key while holding down both Control and Meta C-M-x: a synonym for the above LFD: Linefeed or Newline; same as C-j RET: Return, sometimes marked Enter; same as C-m DEL: Delete, usually not the same as Backspace; same as C-? (See question 3 if you don't know how.)