如何延长显示iPhone应用程序启动画面的时间？

I have added a Default.png picture to my resource folder and the picture is now correctly displayed when the app is launched. But right now I have a problem that the time of the picture shown on screen is just too short and user just doesn't have enough time to take a look at the pic. And idea? ThanksI have added a Default.png picture to my resour