____,____,参差十万人家。 (柳永《望海潮》)
已知函数f(x)=a·2x,x≥02-x,x<0,a∈R,若ff(﹣1)=1,则a=____
—It's red.
—Hi, Bob! Can you tell me ______?
—Sure. The No.5 bus will take you there.