2016 年度“感动中国”人物王锋，三次冲进火场救出多位邻居，自己却不幸遇难。他的英勇事迹说明（  ）

①做出惊天动地的壮举，就能实现人生价值       ②生命的意义不在于长短，而在于对社会的贡献

③只有献出自己的生命，才能延伸生命的价值   ④珍爱生命，让有限的生命焕发光彩

B、C 和 D 项中选出最佳选项。

    Canton Tower is the highest tower in China.1 you stand on top of the tower, you can get a bird's-eye view of the Pearl River. At weekends, people in Guangzhou often visit the tower with 2families. Visitors are 3in taking photos of the city at the tower.

    In 2005, workers 4 to build this tower. In 2010, the colorful lights of the tower lighted up the sky for the first time. People spend over four years 5 it.

    Canton Tower is in the center of our city. It is  6to get there by bus or by underground. We can also find 7useful information of the tower on the Internet. For example, there 8 a 4D cinema in it. The tower is open 9 9 a.m. to 11 p.m.

    For people of Guangzhou, Canton Tower is 10work of art and a new symbol of our city.

如图，分别以直角三角形ABC的三边作正三角形，已知AC=6，AB=10，阴影部分的面积分别记为S₁，S₂，S₃，则S₁+S₃﹣S₂的值为（　　）