In short, visitor mode is a method to separate the data structure and behavior of objects. Through this separation, the effect of dynamically adding new operations to an interviewee without making other modifications can be achieved. Simple Diagram:
就快放暑假了，小学生上原康一在放学回家的路上捡到一块大石头。他把石头带回了家，没想到用水一洗，里面竟跳出一只小河童来。小河童对他“咕”的叫了一声，于是康一就给它取名为“小咕”。
徐文长静坐于桌前：汪直狡诈，必下猛药。
You play this kind of game too little, or too one-sided, the simplified version is the threshold, and then the critical strike is perfect when the attack explosive injury must be mentioned, and then according to the version, there will be a long-term battle, the speed income is actually higher, played a lot of the same type of passing by.
小葱看着涌到军营前的各色姑娘傻眼，急忙上奏，请英武帝定夺此事。
Catalytic dehydration theory: mainly refers to changing the thermal cracking process of fibers to dehydrate and prevent the generation of combustible substances.
意大利医务剧，2008年8月29日首播，第一季共18集，讲述米兰一家公立医院的日常故事，不仅有生老病死的喜怒哀乐，也描述了医护人员在工作之外，各自不同的感情和生活。
青天衙门Ⅱ由《将军之爱》、《望子成龙》、《审妻记》、《花轿奇谋》四个部分组成。在一旱雷闷响的夜晚，顺天府街外一名泪水纵横哭泣声只见喊的书童，手持鼓棒正呜鼓喊冤。身任顺天府尹的谭振英听闻。立率人出门，并连夜审问其因。方庆被提到公堂上，泣诉了少爷方之栋与余清莲，本为一对青梅竹马的恋人，但因迫于无奈，清莲流落风尘沦为卖艺之女。方之栋为给清莲赎身，在街头卖字画攒钱。皇天不负有心人，之栋不仅送金杈于清莲做为……
Men's and women's tennis was listed as a competition event in the first Olympic Games in 1896 and the second Olympic Games in 1900 respectively. However, it was cancelled for various reasons and returned to the Olympic family in the 24th Olympic Games in 1988.
皇牌公关香广男被誉为城中盛女救星，常以出位手段帮助单身女性客户找到美满姻缘，自己却独善其身，选择短线恋爱，新上班的客户主任盛花蕾，误会广男及其大哥香善男和同事董天骄、毕奋强合称的supersenior组合喜爱夜蒲寻欢，又见广男为追求下属袁萱将她捧为网络歌手，因而不耻广男的所作所为，直斥他是烂滚港男，籍工作亲近女性。身为袁萱的姑姐袁琛同样对广男恨之入骨，经常在自己的专栏恶意抨击广男，但广男对这一切都不以为意，依旧我行我素，直至前女友突然现身，令各人关系出现戏剧性逆转，引爆前所未有的港男剩女大激战
As a cinerary road fanatic, Xiao Bian's love for Nagoya subway is quite deep. Therefore, please come boldly and safely. Nagoya welcomes you wholeheartedly with all the subways.
我武警特警教官黄沛霖《猎豹》被外派到T国某沿海孤岛，率领一支强悍的外籍特种兵部队执行一次特殊任务。经过浴血奋战，任务完成得非常漂亮。受到特别嘉奖，并准予回家完婚。当黄沛霖兴冲冲地回到故土，等待他的不是新娘和花车，而是父亲的葬礼。他至爱的父亲——一个成功的民营企业家，在竞争一个上亿元投资的水利工程时，竟因心脏病突出不治身亡；他那相爱已久的恋人容雨君也在父亲猝死的当天神秘地失踪。就在这时，律师张宏亮向他们宣读了父亲的遗嘱：莫名其妙地把上亿元家产的70%给自己的副总经理瞿中信——黄沛霖未来的妹夫，而黄沛霖和他的妹妹黄嫣红只分得30%。刚刚得到黄家70%财产的瞿中信提出：如果与黄嫣红结婚就必须作婚前财产公证！这突如其来的一系列变故把黄沛霖给搞懵了……
A first-class pilot needs more than 1,000 hours of safe flight time.
谁都没想到，胡总督如此信任的幕僚，原来是这样一位鳖孙。
王治乾就是吕文心推荐的编辑。
高一，小镇少女方黎与冷面学霸洛言成为同学，那时的洛言对于方黎来说是噩梦般的存在。三年后他们在大学重逢，此时的洛言已经记不起这个曾经的方黎，可阳光小女侠与傲娇恶魔龙的战争继续上演，这一对互怼冤家经历了最好的青春，最终寻回了那段遗失在小时光中的美好，找寻到各自的梦想。
In the previous example of electric lights, a state mode program was completed. First, the Light class is defined, which is also called Context here. Then in Light's constructor, to create instance objects for each state class, Context will hold references to these state objects in order to delegate the request to the state objects. The user's request, that is, the action of clicking button, is also implemented in Context, with the following code:
Modern hockey emerged in England in the second half of the 19th century. The 4th Olympic Games in 1908 was listed as a competition event.
