D > B enters the synchronized block, and since instance is not null at this time, it immediately leaves the synchronized block and returns the result to the program calling the method. E > At this point, thread B intends to use the Singleton instance, only to find that it has not been initialized, so an error occurs. Therefore, there is still the possibility of errors in the program. In fact, the running process of the program is very complicated. From this, we can see that it is more difficult and challenging to write programs especially in multi-threaded environment. We further optimized the program:
故事开始于一九三四年的山西省汾西县，小伙计出身的陈海子收货款时遇到正在执行潜伏任务的共产党区党委书记雷钧，这次偶遇为他心中埋下了一颗红色的火种。为加入共产党，他不惜以身犯险，潜伏在晋军兵工厂，几经考验，终于成为一名共产党员并改名为陈志，同时也收获了同是党员的东家之女黎梅的爱情。但黎梅表哥，身为晋军特务的商见诚的欺骗使得共党地下组织瞬间瓦解，陈志九死一生脱离险境，却被党组织戴上“特务”的嫌疑，自此一生背负着这个根本不属于他的包袱。在同志们的帮助下，陈志建立起汾西最早的游击队伍，从此开始了八年抗战、四年解放战争，结下了一群对他无比信任的战友同志，立下无数大功却始终被“历史问题”影响。解放后，陈志当起了县委书记，他鞠躬尽瘁，为当地民生的发展立下汗马功劳，他对革命理想的忠诚感动了身边的战友、亲人，甚至对手。终于，在所有人的不懈努力下，陈志的“历史问题”得以澄清。
Column Introduction: Zhengda Variety Show has a large number of film sources. The film is the eternal brand of Zhengda Variety Show. In the new version of Zhengda Variety Show, the film is still the main section of the column. Therefore, while preserving the original columns such as "The World Is Wonderful", new columns such as "Guinness World Records" and "Action X" have been added. "Zhengda Variety Show" has been the brand column of the channel it broadcasts since its debut, with a very distinctive personality and stable ratings. First broadcast time: 18:00 every Sunday, rebroadcast time: 12:30 every Monday, and 09:30 every Sunday, and solo broadcast channel: CCTV-1
可是赵王歇不知道是怎么想的，也不第五〇〇章俘获赵王知道是没想到这一层，还是担心赵王大纛会引来汉军是士兵的攻击。
该剧改编自我国作家何署坤上世纪90年代创作的经典童话小说《蜜里逃生》，此书出版后被改编成话剧、音乐剧、电视剧等多种形式。迄今为止40集电视剧《蜜里逃生》已在包括中央电视台在内的全国所有地区的1000余家电视台播出。《蜜里逃生》在全国儿童剧创作上已经颇具影响，建立了比较稳定的观众群，并为进一步制作动画片和漫画产品打下了良好的基础。目前，三维动画《蜜里逃生》正在制作中。 五年级旦旦因语文期末考试差两分就100分而被爸爸妈妈取消了带他去旅游的承诺，孤独伤心的旦旦放走了被爸爸关在实验室的蓝眼睛蜜蜂，也无意中放走了爸爸试验培育的蜜蜂——WD蜂。 蓝眼睛（蓝蓝）回报旦旦吐了一口蜜让旦旦尝，旦旦终于如愿变成了一只自由飞翔的小蜜蜂，与蓝蓝飞上了晴空……
2019年5月，几十位作家来到山西汾阳的一个小村庄，他们在这里谈论乡村与城市，文学与现实。影片以此为序曲，交响乐般地以18个章节讲述出1949年以来的中国往事。出生于上世纪50年代、60年代和70年代的三位作家贾平凹、余华和梁鸿成为影片最重要的叙述者，他们与已故作家马烽的女儿一起，重新注视了社会变迁中的个人与家庭，让影片成为一部跨度长达70年的中国心灵史。
美丽活泼的巴伐利亚公主茜茜生长在一个大家庭里。父亲是一个无忧无虑的的贵族，经常带着茜茜去山上打猎。母亲鲁多维卡是一位忠心耿耿的家庭主妇。她的姐姐苏菲的儿子弗兰西斯是奥地利的王位继承人，打算让年轻的国王在他的生日庆典上与茜茜的姐姐海伦订婚。当茜茜跟随母亲和姐姐来到奥地利时，一次偷偷溜出去钓鱼，与弗朗西斯邂逅，从此国王便无可救药地爱上了天真的茜茜，并最终违背母亲的旨意，在庆典上宣布茜茜为自己未来的皇后。
To what extent has the world driven XX sales? Not to mention 2-4G, there are Chinese versions on the simulator. . . The problem is that GU is only played on the host computer, so many of the 10 million or so new players in the world must have bought XX.
The Liskov Substitution Principle (LSP) is one of the basic principles of object-oriented design. The Richter substitution principle says that wherever a base class can appear, subclasses can certainly appear. LSP is the cornerstone of inheritance reuse. Only when derivative classes can replace base classes and the functions of software units are not affected can base classes be truly reused, and derivative classes can also add new behaviors to base classes. The Richter substitution principle is a supplement to the "open-close" principle. The key step to realize the "open-close" principle is abstraction. The inheritance relationship between the base class and the subclass is the concrete realization of abstraction, so the Richter substitution principle is the specification of the concrete steps to realize abstraction. --From Baidu
金南佶将在剧中饰演医术高明的朝鲜男人许林（音译），个高、帅气，对任何事都悠悠哉哉很随性。金雅中将出演外表冷酷、内心带着伤痕和秘密的首尔女性崔延京（音译），是某医院胸外科医生，外貌靓丽、妆容精致，有着像模特一样的身材，但说话豪放、表情冷酷。是在医学院就读期间连续6年拿第一的“行走的医学书”。 该片讲述公认的朝鲜第一针灸师许林因为出生贫贱而四处碰壁，因此失去初心。之后，他来到400年后的未来，即2017年的首尔，遇到了现代医学的信奉者、性格豪放的崔延京后发生的故事。这是一部融合了现代医学和传统韩医学，在魅力的历史长流中以实际存在的人物为主人公的首部男女主往返双穿越剧（男主穿去现代，女主穿去古代）。
警界老油条阿辉（周润发 饰）生性风流，凭借自己父亲昔日手下沾叔（黄沾 饰）的维护，阿辉在警局虽然得不到升迁，但也落得清闲。新进警员曹里昂（李元霸 饰）的到来打破了这一切，曹大胆甚至莽撞的办案方式连累阿辉大出洋相，阿辉虽恨曹里昂，但碍于上司命令，不得不与曹搭档。
大军一路前行，尹旭见到沿途的风景，不由地感叹，这里是后世那千沟万壑，苍凉贫瘠的黄土高原。
The singleton mode is characterized by two classes (one business class construction method is private, and the other factory class is responsible for saving singletons of business classes. Pay attention to the use of multithreading)
说不尽《石头记》的情爱故事，演不尽《红楼梦》的悲欢离合。 剧随宝玉的眼睛，走进大观园，目睹金陵十二钗的人生悲剧，折射金陵四大家族的荣辱兴衰。 优美的山水园林，抒情的越剧音乐，演唱出《红楼梦》中一系列女性悲歌，王熙凤、林黛玉、薛宝钗、元春、迎春、探春、惜春、湘云、秦可卿、尤二姐、尤三姐、金钏、司棋、晴雯、鸳鸯、紫鹃、袭人，还有李纨、妙玉…… 宝玉目睹这些‘水做的骨肉’一个个走的走了，死的死了，他的心也空了。
At that time, after the post was sent out, several pregnant women were fooled before the victims and replied that they wanted baby supplies. However, due to various reasons: some were not pregnant with male babies, some were not pregnant for enough months, and some were accompanied, so the murderer did not attack them. These pregnant women were lucky to escape.
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Methodology is pieced together one by one in this way. After a long time, it can become its own methodology if it is systematized and systematized.
Then we must have written the following code before:
这道路挨着山坡，塌陷冲刷的痕迹明显，这沟是被夏季山洪冲出来。
