氧气与血红蛋白结合的部位是（    ）

                                                                                                      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。

用反证法证明“在同一平面内，若a⊥b，a⊥c，则b∥c时，第一步应假设（　　）

—Most people said the film Let The Bullets Fly was wonderful _____ they watched it.
—I agree with them, and I like it very much!