You most likely did a push-up at some stage in your life before beginning CrossFit, but you may not have done the full spectrum of motion pushups we use in CrossFit. Your arms should be absolutely straight at the top, and your chest should be in touch with the ground at the bottom.
7 Rounds for Time 10 Hand-Release Push-Ups 10 Alternating Dumbbell Clean-and-Jerks (50/35 lb) 10 Burpees over Dumbbell Time Cap for each round: 3 minutes