Hi, I am new the Macbook Pro and have questions regarding battery needs your help. 1) If my MacBook Pro is fully changed and I plan to put it to sleep mode, do I still need to let AC adapter plug in? 2) Let the computer to sleep or turn off is better when I don't use it? 3) What's the normal "Fully Changed Capacity"? Because I saw it changed from time to time when I check in "Apple system profiler"? Appreciate your views and answers to the above questions. Thank you very much in advance!!!