You can't without an action replay,trading, or poke-transfer.
Yes; Zekrom is the main legendary in Pokemon White.
You cant without action replay
You can't without trading with someone that has black.
Not without trading from another game.
No.
no it is immpossable unless you have an action replay with the Pokemon modifier code
i don't think you can without trading from someone who has one or buying Pokemon white or using a cheat device, zekrom is version exclusive to Pokemon white.
other than trading none that i know of
yes by trading or you can breed a zoroak
it just randomly apperrs like raiku ,suicune, and entie on Pokemon soulsilver/heratgold.
Not without trading or starting again. Find someone on the GTS.
Diglett can not be obtained in Black and White without trading or cheating D=.