CMOS 器件不用的输入端必须连到高电平或低电平, 这是因为 CMOS 是高输入阻抗器件, 理想状态是没有输入电流的. 如果不用的输入引脚悬空, 很容易感应到干扰信号, 影响芯片的逻辑运行, 甚至静电积累永久性的击穿这个输入端,...
至于原因我个人只能按照float脱离文档流来解释了(可以理解成脱离了正常的文档显示顺序)。不知道对你有没有帮助，下面给你一个w3c教程的地址，很权威的标准教程，慢慢学习吧http://www.w3school.com.cn/css/css_positioning_...
Robinson and "Friday" helped the captain to subdue the rebellious sailors and recapture the ship.He left the crew on the island and returned to Britain with Friday and the captain. Robinson had been away fro...
和我整个世界的一半 I turn left , and you turn right 我向左转,你向右转 Between the star now straight can see 现在的恒星之间直接可以看到 Don't give up, when we fight 不要放弃,当我们战斗 While all we a...
高度参数设为自动，div的大小就会随内容的多少而改变。三个并排的DIV是不可能自动居中显示的，需要设置浮动属性，通过设定边界值微调才行。
saying goes,“food is the first necessity of the people ”.Indeed food, as the first factor of survival, plays a very significant role in our daily lives. In recent years, however, the food safety issues...
Alexander Selkirk, an 18th-century Scottish sailor who spent almost five years alone on a desert island. This novel is famous for its lovely details and its expression of belief in man's ability when left ...
Locked outside the people that we used to be,Come back to me.We're half a world away,Still pretending that there's nothing wrong,Just talk to me,And make my half world whole.(Part 3)I turned left ...
1 夏天的飞鸟，飞到我的窗前唱歌，又飞去了。秋天的黄叶，它们没有什么可唱，只叹息一声，飞落在那里。Stray birds of summer come to my window to sing and fly away.And yellow leaves of autumn,which have no s...
clear在w3.org官方的解释 The clear property indicates which sides of an element's box(es) may not be adjacent to an earlier floating box. 盒子的边不和前面浮动盒子相邻 因为html是上下的文档流，所以这...