题目

甲、乙两人在直线道路上同起点、同终点、同方向，分别以不同的速度匀速跑步1500米，先到终点的人原地休息，已知甲先出发30秒后，乙才出发，在跑步的整个过程中，甲、乙两人的距离（米）与甲出发的时间（秒）之间的关系如图所示，则乙到终点时，甲距终点的距离是_________米. 答案：【答案】175【解析】试题解析：根据题意得，甲的速度为：75÷30=2.5米/秒，设乙的速度为m米/秒，则（m-2.5）×（180-30）=75，解得：m=3米/秒，则乙的速度为3米/秒，乙到终点时所用的时间为： =500（秒），此时甲走的路程是：2.5×（500+30）=1325（米），甲距终点的距离是1500-1325=175（米）．The Aztecs were a native American people who lived in Central American between the 14th and 16th centuries．The Aztecs were originally from North America，but they migrated south to the area that is now modern Mexico in search of a better place to live．When the Aztecs first arrived in Central America，they were subjects of the Toltec people who already ruled the area．But，when the Aztecs had been there for about 100years，they stared to set up their own empire，this empire grew to cover the area that is now Mexico and Guatemala．1.Where were the Aztecs originally from？ A. Latin America．B. Central America．C. South America．D. North America．2.What was the Aztecs empire set up？ A. In the 14th century．B. In the 15th century．C. In the 16th century．D. In the 17th century．