下面诗句描写的月相是（    ）

暮江吟（白居易）

一道残阳铺水中，半江瑟瑟半江红。

可怜九月初三夜，露似珍珠月似弓。

（2012•阜新）下列交通标志是轴对称图形的是（  ）

阅读理解

     Linda was a sixteen-year-old girl in Canada. She was feeling bad for several days. Her mother took her to a hospital and the doctors found out that she had cancer.

     Linda's life changed. She began to go to the hospital often for treatment（治疗）, and she also became depressed.

     The hospitals and the doctors were good, but Linda did not have hope herself. Linda's mother called a flower shop close to the hospital. “I want some beautiful flowers for my daughter. She is a teen girl with cancer.” She told the shop owner.

     Later, the flowers arrived. Then Linda saw something unusual. It was a card. It read:Linda, I own (拥有) this flower shop. I had cancer when I was fifteen years old. I am 24 years old now. Good luck. My heart goes out to you.

                                                                              Yours,

                                                                               Alice

     Linda smiled. She finally felt some real hope. She found the will (意志) to 1ive.

     Little things make a big difference. All of us can give little things like kindness, encouragement and hope to others.

平面几何中，若△ABC的内切圆半径为r，其三边长分别为a，b，c，则△ABC的面积S=$\frac{1}{2}\left(a+b+c\right)·r$．类比上述命题，若三棱锥的内切球半径为R，其四个面的面积分别为S₁，S₂，S₃，S₄，猜想三棱锥体积V的一个公式．若三棱锥P﹣ABC的体积V=$\frac{2\sqrt{2}}{3}$，其四个面的面积均为$\sqrt{3}$，根据所猜想的公式计算该三棱锥P﹣ABC的内切球半径R为（　　）