（2015•东营）如图，在Rt△ABC中，∠ABC=90°．AB=BC．点D是线段AB上的一点，连结CD．过点B作BG⊥CD，分别交CD、CA于点E、F，与过点A且垂直于AB的直线相交于点G，连结DF，给出以下四个结论：①$\frac{AG}{AB}$=$\frac{AF}{FC}$；②若点D是AB的中点，则AF=$\frac{\sqrt{2}}{3}$AB；③当B、C、F、D四点在同一个圆上时，DF=DB；④若$\frac{DB}{AD}$=$\frac{1}{2}$，则S_△ABC=9S_△BDF，其中正确的结论序号是（　　）

读某次台风从17日至21日移动过程示意图，回答以下问题。

    Success never comes easy. How many of you have heard of successful people who haven't made any effort? People often have to overcome failures ____ they can accomplish something great. They usually don't find success from the very beginning.

    Van Gogh sold only one painting during his lifetime, but this didn't stop him from completing over 800 painting. Thomas Edison ____(fire) from his first two jobs for lack of competence. Later, as an inventor, he tried 1,000 times ____ (create) the light bulb, without success. He was confident in ____ (he), and____ (eventual) he did success. When____ (ask), “How did it feel to fail 1,000 times?” Edison replied, “I didn't fail 1,000 times. The light bulb was ____ invention with 1,000 steps.

    These successful people have set good____ (example) to us. They wouldn't have achieved their success if they____ (abandon)their dreams. Believe in yourself and try your best, and success will not be far ____ you.