产品国际标准是哪些

The principle of opening and closing means opening to expansion and closing to modification. When the program needs to be expanded, the original code cannot be modified, but the original code should be expanded to achieve a hot plug effect. Therefore, a summary of one sentence is: in order to make the program scalable, easy to maintain and upgrade. To achieve this effect, we need to use interfaces and abstract classes, etc. We will mention this point in the later specific design.150. X.X.206　日英同盟Altitude phobia can endanger flight safety. After suffering from high-altitude phobia during the flight, the pilots felt that their flying space was infinite and vast. They and the plane were far away from the earth and flying in an infinite space. They were very small. They had a premonition that this high-altitude space was the only factor of human-computer insecurity, and only they could leave this environment quickly. Those who have experienced a high degree of fear in childhood are prone to this disease.这才是尹将军一直以来希望的情形，项羽和刘邦打的你死我活，都无暇顾及旁的。Detection and Defense of DDOS Attacks in Metropolitan Area Network外层空间的不明飞行物体将降落地球，专家们正在搜寻飞碟的降落地点。此时，一名电力公司的电线工人李察德瑞佛斯，在户外检查电力问题时， 竟发觉自己受到天空中异光的包围，从此他的心中就不停的出现怪异的景像、与5个奇怪的音符，为了解开这个不可思议的谜 ，他像着了魔一样，亲自与外星人作了第一次面对面的接触，并展开了一段外层空间之旅。