孙亮同学参加十五米折返跑体育现场测试，共计跑了52次，下图中能分别表示该过程中他体温变化和单位时间内耗氧量变化的曲线是（　　）

    London is one of the most popular sites in the world for tourists to visit.If you are planning a trip to London in the future,you're lucky.There are a variety of attractions for you to enjoy.

    One of the most popular tourist attractions in London is the Tower of London.Founded more than 900 years ago, the Tower of London is one of the world's most famous towers and has changed a lot.Here,you can also find the seven ravens（乌鸦）which live in the Tower.There is a story that says: If there are no ravens in the Tower, the Tower and the kingdom will fall.There are also lots of tours,exhibits.and special events that you can enjoy throughout the year.

    Another popular place to visit is Westminster Abbey.It was set up in 1065 by Edward the Confessor.Visitors to Westminster Abbey can enjoy its beautiful special Gothic architecture（哥特式建筑）.There are also lots of memorials of Kings and Queens to enjoy.Excellent transportation is available here by bus or tube from many locations in London.

    Buckingham Palace is another place with a rich history to discover.It's the official London residence（住处）of Queen ElizabethⅡ.During August and September,you can visit the State Rooms and see the Changing of the Guards.The Queen's Gallery is open to the public daily.Checking the official timetable before you make sure to visit the Palace is a must,because it is not open year round.

设a, b∈R,a+bi=5+3i (i为虚数单位),则a+b的值为____.

排列句子。

____湖当中，水面平静得像一面镜子，绿得像一块碧玉。几只游船正在上面慢慢滑过，几乎不留一点痕迹。

____湖岸边，垂柳成行，知了叫个不停。一阵微风从湖面上吹来，好凉爽啊！

____青龙湖的景色可真美啊！

____星期天，爸爸带我到青龙湖去玩。

____在湖边的浅水里，十几个孩子正在游泳、嬉戏、打闹，玩得真开心。