题干

近年来,随着经济的快速发展,我市不断加大道路交通基础设施建设,大部分乡镇的道路均提档升级,极大改善了公路交通条件,小张同学和爸爸从某镇开车到天门城区,在经过A处时,车辆上的电子表显示“09:12”,到达B处时,车辆上的电子表显示“09:27”,B处另外还立着一个写有“限速40”的标牌,如图所示,

(1)从A处到B处,小车的平均速度为多少千米每小时?

(2)从B处到天门城区,按交通标牌上的要求行驶,最快还要多长时间可以到达?

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答案(点此获取答案解析)

解:(1)小车从A处到B处所用时间t=09:27﹣09:12=15min=0.25h,
由图可知,从A处到B处的距离s=30km﹣12km=18km,
小车的平均速度:v=
s
t
=

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    In the 1600's when the Spanish moved into what later was to become the southwestern United States, they came across the ancestors of the modern-day Pueblo, Hopi, and Zuni peoples. These ancestors, known variously as the basket makers, the Ancient ones, had lived in the area for at least 2000 years. They were an advanced agricultura people who used irrigation to help grow their drops.

    The Anasazi lived in houses constructed of earth and wood. Anasazi houses were originally built underground and were entered from the roof. But around the year 700 A. D., the Anasazi began to build their homes above ground and join them together into multistoried complexes, which the Spanish called villages. Separate underground rooms in these villages—known as kivas or holy places—were set aside for religious ceremonies. Each kiva had a fireplace and a hole that was believed to lead to the underworld. The largest villages had five stories and more than 800 rooms.

    The Anasazi family was ruled by women. The sacred objects of the family were under the control of the oldest female, but the actual ceremonies were conducted by her brother or son. Women owned the rooms in the village and the crops, once they were harvested. While still growing, crops belonged to the men who, in contrast to most other Native American groups, planted them. The women made baskets and pottery; the men wove cloth and made jewelry.

    Each village had two chiefs. The village chief dealt with land arguments and religious affairs. The war chief led the men in fighting during occasional conflicts that broke out with neithboring villages and directed the men in commnity building projects. The political and social organization of the Anasazi made it almost impossible for outer groups to conquer them.