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:
A complete computer system consists of hardware and software. As the name implies, hardware is the physical equipment that can be seen and touched in the computer, such as the host computer. Software, on the other hand, is relative to hardware. It refers to various programs and related documents needed to run on the computer, such as a drawing software or a gobang game. Computer hardware and software are indispensable. Hardware is the material basis on which software can work and is the "body". Software is the soul of the computer and the core of controlling and operating the computer. They complement each other and form a complete computer system. From the appearance, the computer includes: monitor, host computer, keyboard, mouse and sound box.
很快，她发现自己不用为难了，因为她走不了了。
As a person who knew crayfish very well from an early age, I also lost money because I was too confident and thought I was smarter than others. Therefore, novices must be careful when entering. They should not think it is easy to raise crayfish and think it is easy to earn money.
(Draft for Comments)
该剧讲述了一众拥有音乐梦想的少男少女，经历了各种挫折，在相互扶持中共同成长，最终收获友情、爱情和梦想的励志故事。
第2季动画中，将刻画升入私立风林学园中学部的主人公茂野大吾的活跃身姿。主视觉图中，除成长后的大吾和佐仓睦子等人的身姿外，还描绘了将在第2季中登场的风林中学棒球部的成员。
常开歌是一个80后青年农民，人称“开哥”。见多识广的他立志要在家乡做一番大事业，无奈时运不济，干啥啥不成、烧香佛转腚。一筹莫展之际，前女友谷小燕衣锦还乡，令开哥自惭形秽。
大启朝灭亡，出现南楚、东宋、西凉，以及北燕四国。作为大启朝的后裔巫教教主为光复大启朝，故意留下一段蝴蝶女婴的预言，预言说南朝出蝴蝶女婴，东宋如果遇到不杀将会灭亡，从此东宋陛下最大的心愿便是除去蝴蝶女婴。东宋太子连杪尘从小便被这预言胁迫，因而更想解开预言的神秘面纱，故特亲自乔装混进南楚最大的酒楼来调查蝴蝶女婴。白蝶和连杪尘相遇，本应是命中克星的两个人却相互爱慕起来，即使经历种种磨难，也改变不了两个人之间的爱。
2012年1月，深夜开始悄悄播放的“孤独的美食家”终于迎来第7季了！众所周知，上季season 6从大阪的味道开始播出，但这次season 7重返初心，并开始与市井中不为人知的奇妙美食相遇。在“孤独的美食家”中，除了会有最强菜品的肉料理和最受欢迎的中华料理等丰富多彩的菜单外，必不可少的日本料理将继续登场，并且还有出差篇等，节目魅力十足。另一方面，我们还将带来新的惊喜，带来不同的挑战，比如我们还没有推出的美食类型的外观，或者合并新产品。 敬请期待。
小提琴的流浪从未间断，从盗墓者，到吉普赛人，到为之自杀的作曲家波普，再到文革期间上海的一位音乐老师。这期间，无论拥有者是否明白小提琴真正价值，都逃不出它的魔力。终于，有鉴别专家知道了小提琴的秘密——它的外壳染着三个世纪前一位大师的血和泪。
面临内忧外患，崇祯皇帝急召吴三桂入京,临危受命,北御强敌，南卫京师,但事败垂成.多尔衮利用李自成副帅刘宗敏抢夺陈圆圆，策反吴三桂，使得清军兵不血刃,长驱直入,多尔衮辅佐清廷幼君福临在北京登基，建年号为顺治元年.
张哲修三次相遇赵安娜，三次损失钱财，内心忿恨发誓要找机会讨回。朴比利表示已对赵安娜忍无可忍后，赵安娜于雨夜独坐豪华游艇喝闷酒，一不小心身坠大海。因为尸首找不到，朴比利认定赵安娜已死，掩饰不住兴奋，但赵安娜被人救上岸送进了医院，只是失去记忆。医院里，张哲修发现失忆的赵安娜，正要请保姆照料三个侄子的他灵机一动，哄骗赵安娜说两人是男女朋友关系，唤她“罗丧失”将她接回了家中……
读日本最好的精英大学的四年级学生加藤（藤井），毛泽东（滨田），幸喜（前田）和俊（吉田）仅学习了一段时间，但大学毕业后将成为成年人了。 ！ 还有很大的启发。 根据他们的观点，一部纪录片相机经过艰苦奋斗，有时会罢工，有时会失败，有时会忘记目的，并交换热烈的友谊，以便结识到理想的女人。
何永强失去了动力，也没有了计谋，他知道一切只能从长计议了。
这个时候他注意到陈余对常山国的攻势，这个时候无疑是张耳最孤独无助的的时候，若是现在将他拉到自己一方，自然最好不过。
3. The outer epidermis of the regular network cable also has certain ductility, also called elasticity. If the outer epidermis is inelastic, it is easy to break. Therefore, when buying the network cable, you can reduce a 0.5 meter long network cable and pull it to both sides. See if there is a crack in the middle or if the epidermis can extend to both ends. If there is no crack in the middle during the pulling process, and the epidermis can also extend to both ends, then the epidermis of this network cable meets the standard. In addition, we should pay attention to a problem. In the process of pulling, although some network cables have no cracks, there are obvious signs of whitening and thinning in the middle, which is also not in line with the standard.
Why is it so important to simply divide three categories?
尹旭甚至有种感觉，这像是一个玩笑，轻轻笑道：陈先生，你现在上将军帐下不是也很好吗？或是前去霸上见刘沛公，相信他也会到履相迎的，为何单单会选择可能性最小的的在下呢？陈平为何会选择自己？这是尹旭目前最想知道的答案。
A. Flight qualification;
