Insufficient end clearance on newly fitted piston rings in a diesel enginewill cause the rings to（） ["jam in the most worn part of the cylinder when the rings expand","break in the most worn part of the cylinder when the rings expand","wear eccentrically on the side opposite the end gap","overheat and jam at the top center on the combustion stroke"]
在众多出土的石器遗址中，最早、最具有代表性重要遗址是黄河上游的马家窑文化和下游的仰韶文化。
操作窗口内的滚动条可以（）。 ["滚动显示窗口内菜单项","滚动显示窗口内信息","滚动显示窗口的状态栏信息","改变窗口在桌面上的位置"]
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"]
什么是完成推销重任的首要保证？
