下面是《长征组歌》中的几个片段，请根据所学知识回答问题。

片段一：  红旗飘，军号响，子弟兵，别故乡。王明路线滔天罪，五次“围剿”敌猖狂，红军急切上征途，战略转移去远方。男女老少来相送，热泪沾衣叙情长，紧紧握住红军的手，亲人何时返故乡？

片段二：  万众欢呼毛主席，马列路线指航程。雄师刀坝告大捷，工农踊跃当红军。英明领袖来掌舵，革命磅礴向前进。

片段三：  横断山，路难行。敌重兵，压黔境。战士双脚走天下，四渡赤水出奇兵。乌江天险重飞渡，兵临贵阳逼昆明。敌人弃甲丢烟枪，我军乘胜赶路程。调虎离山袭金沙，毛主席用兵真如神。

片段四：  水湍急，山峭耸，雄关险，豺狼凶。健儿巧渡金沙江，兄弟民族夹道迎。安顺场边孤舟勇，踩波踏浪歼敌兵。昼夜兼程二百四，猛打穷追夺泸定。铁索桥上显威风，勇士万代留英名。

片段五：  雪皑皑，野茫茫，高原寒，炊断粮。红军都是钢铁汉，千锤百炼不怕难。雪山低头迎远客，草毯泥毡扎营盘。风雨侵衣骨更硬，野菜充饥志越坚。官兵一致同甘苦，革命理想高于天。

要提高某一机械的效率，可以采取的正确方法是（   ）

函数$f\left(x\right)=\sin x-\cos \left(x+\frac{\mathrm{\pi }}{6}\right)$的值域为（  ）

    It was a busy morning. At about 8:30, an 80-year-old elderly gentleman came to the hospital. I heard him saying to the nurse that he was in a hurry to meet someone at 9:30.

    The nurse made him take a 1 in the waiting area and told him it would 2 him at least 40 minutes to wait. The gentleman 3his watch and there was much worry on his face.

    Since I was not4that morning—my patient didn't5at the appointed(约定的) hour, I said that I would examine his wound. When I took care of his wound, I asked him if he would go to see another doctor.

    The gentleman said no and told me that he6to go to the nursing home to eat breakfast with his7 He told me that she had a special disease. I asked if she would be8 if he was a bit late. He replied that she9knew who he was. That she had not been able to10him for five years. I was11 and asked him, “And you12go every morning even though she doesn't know who you are?”

    He smiled and said, “She doesn't know me, but I know who she is.” After hearing this, I could hardly hold back my 13.

    Now I14that for husband and wife, true love means accepting her or his all. The happiest people don't necessarily have the best of everything; they just make the best use of everything they have.15isn't about how to live through the storm, but how to dance in the rain.