Hello! I'm Victor.I have a bed, a desk, two chairs and a computer in my bedroom.My bed is small but very nice.It's blue because I like blue very much.My desk is big.It's white.You can see a computer and so many books on it.I do my homework here.I have two chairs.One is big and one is small.The big one is near the bed.The small one is near the window.I like my room.

                                                                                                      登楼
                                                                                                     杜甫
                                                                             花近高楼伤客心，万方多难此登临。
                                                                             锦江春色来天地，玉垒浮云变古今。
                                                                             北极朝廷终不改，西山寇盗莫相侵。
                                                                             可怜后主还祠庙，日暮聊为梁父吟。

孙中山说：“经过那次血战之后，外国人才知道中国还有民族思想，这种民族是不可消灭的。”发生在20世纪初的“那次血战”指的是（   ）

下列光现象及其分析，正确的是（   ）