二次函数y＝x²－6x＋5的图像的顶点坐标是（     ）

物质的物理属性有很多应用。请你写出下面物质属性应用的实例（举一例即可）：

铝合金的密度小，其应用有____；铜的导电性强，其应用有____。

阅读下面文段，回答后面问题。
         小草偷偷地从土里钻出来，嫩嫩的，绿绿的。园子里，田野里，瞧去一大片一大片满是的。坐着，躺着，打两个滚，踢几脚球，赛几趟跑，捉几回迷藏。风轻悄悄的，草软绵绵的。
         桃树、杏树、梨树，你不让我，我不让你，都开满了花赶趟儿。红的像火，粉的像霞，白的像雪。花里带着甜味儿；闭了眼，村上仿佛已经满是桃儿、杏儿、梨儿。花下成千成百的蜜蜂嗡嗡地闹着，大小的蝴蝶飞来飞去。野花遍地是：杂样儿，有名字的，没名字的，散在草丛里像眼睛，像星星，还眨呀眨的。

    The Sea Life Centre is a Really Exciting Place
    Good morning, everyone.1 to the new Sea Life Centre at Plymouth.The Sea Life Centre is a really exciting place. There are so many things to2here and everything is enjoyable. It costs $3.76 for adults ,  $2 for children and 3 for over sixties and school groups. It's 4 from 9:00am to 4:30pm every day except 25^th and 26^th of December.Special 5include hourly feeding times for all the different animals and fish, and shows in the sea life theatre. 6  is always there to answer questions about what you've seen. 7 you are in a group of six or more people, we  8 give you a special guided tour of the centre. But you 9 to arrange(安排 ) this at the information desk when you 10.
    The latest attraction(吸引人的事) is a big 11 tunnel(隧道 )you can walk through. All around you, you will see fish swimming--- sometimes even over your head. You certainly have the 12view(景色 ) of the undersea world. Children 13 it and it's really amazing for adults, too.
    When you get 14, there is a relaxed family dining room serving food.That's all. For 15information, phone 091743-564219. Have a good time! Thank you.