— , I don't know.
—_______. I'll do it right away.
- ________ He always communicates with our parents in his free time.
一 _____________. I am proud of you.
一 .
—_________ Don't say no before you really try.
— . I've had enough.
— . I've got another copy.
— Her name's Mary.
— . His name is Dale.
—________. There isn't any cloud in the sky.
—________. It'll be on again in two hours.
— It's Monday the 5th.
— ___________________ ! Let's go!
— ______________.
— ________
— No, but don't worry. I used to(曾经)live here, so I know it like the back of my hand.
What does "know it like the back of my hand" mean here? You may answer it in Chinese or English.