考古发现最早艺术品出现于旧石器时代中期。
What is the major advantage of high altitude observations?() Errors due to unusual parallax are eliminated。 The same body can be used for a fix from observations separated by several minutes。 The declination is the only information needed from the almanac。 The semidiameter correction of the sextant altitude is eliminated。
在教育训练过程中,应根据不同训练课目的目的,内容和受训人员的具体情况,采取多种方法,启发和调动受训人员的主动性、积极性,这种方法称为启发式教育。
Before being shut down, a diesel engine should idle a few minutes in orderto () prevent governor surging at shutdown。 make sure the fuel nozzles are flushed clean。 prevent pressure buildup in the fuel lines。 prevent damage from localized overheating。
影响碳酸化分解过程的主要因素有哪些?
在Windows中,从Windows图形用户界面切换到“命令提示符”方式以后,再返回到Windows图形用户界面下,可以键入()命令后回车。