------Can you tell me _________ traveling to Dalian?

------About two hours by plane.

A．how much it costs

B．how soon it takes

C．how long I will take

D．how many hours I will spend

电视画面上极明亮景物和极暗景物交界处，景物亮度间距悬殊的交界处，由于强光向弱光处漫射，会出现一种（）现象。