Don’t let me down. (
I’m behind you. (
The phrase "on the ball" is a conventional usage, which means smart, diligent, or expertly. Here is an example: That banker is really on the ball upon his business.
The phrase "count on" means to depend on or rely on.
Example: Is there any document I can count on?
Another mean of "count on" is to anticipate or to be confident of.
Example: I extremely count on getting a raise of my pay next year.
The term "roll out" means produce in high volumes, e.g. Sony already has rolled out high-end notebooks using Vimicro’s silicon.
“Don’t complain or just simply admire other people. Try to understand what the hell makes difference between you and them. If it is communication, learn English; If it is technical, do your homework. Always remember, we are smart Chinese.”