老师一边讲课一边在黑板上写字

At that tail of the warhead, the drag armour-piercing firebomb is filled with a drag agent and a fireagent, Under the pressure of propellant propelling warhead, it will spontaneously ignite to produce open flame, So it can break through the oil drum and ignite or detonate the gasoline. However, the old-fashioned traced armour-piercing firebombs have obvious trajectories due to traced light when they are launched. Therefore, it is very easy to expose oneself while pointing targets to friendly forces. Therefore, the new tracer armour-piercing firebombs now equipped all start to burn and emit light only after the projectile flies out of the muzzle for a certain distance (the generally set safe distance is 100 meters, which makes it impossible for the enemy to judge the firing position with tracer ammunition, while targets within 100 meters do not need to be indicated by tracer), The principle is generally to ignite the tracer and combustion agent carried by the projectile by accumulating the heat generated by the warhead's friction with the air after flying for a certain distance to a certain extent.民国初年，军阀混乱，列强侵占，山河破碎，民不聊生。仁人志士霍元甲在国家内忧外患之际满目疮痍，决心练武强身救国，开办“精武馆”并创衍出一套精妙的拳术“迷踪拳”，让外国武者闻风丧胆，洗刷列强给中国人枉加的“东亚病夫”的耻辱，显示出了中华民族的凛然正气。后由于当权者的腐败懦弱，一代宗师竟被列强走狗，民族败类下毒身亡，谱成一部可歌可泣的民族正气诗篇。[Basic Requirements for Experience] The memory of the mobile phone meets 2G or more (this mode does not support models with 2G or less in it yet, and the government will continue to optimize and will be compatible with more models in the future.)韩信轻轻摇摇头，匆匆忙忙往书房赶去。海瑞妄言诬陛下，其心可诛，但依臣所见，反是万万不可诛的。