汽车以10m/s的速度在公路上匀速行驶，刹车后以2m/s²的加速度匀减速直线运动，求刹车后4s末的速度和8s内汽车通过的位移．

    Yesterday ____ (is) sunny. Jim ____ (go) to the zoo with his friends. They ____ (buy) some ice cream and ____ (see) many animals. They ____ (have) a good time.

“为了谁”是开展党的群众路线教育实践活动必须回答的重大问题之一。“为了谁”就是要切实维护和解决人民群众最关心、最直接、最现实的利益问题。这是（    ）

①我们党的宗旨所要求的   ②实现同步富裕、同等富裕的需要

③科学发展观的具体体现   ④立党为公、执政为民的根本要求

    Why does the Leaning Tower of Pisa in Italy lean? It leans because of a mistake. It has leaned almost since the day the builders b____ it.
In 1774, the people of Pisa in Italy wanted to build a bell tower. They wanted the tower to be the m____beautiful bell tower in Italy. The city needed a bell tower because the church(教堂) did not have o____ . As soon as the first floor of the building was finished, the tower started to lean. Builders t____  to make the building straight again as they added more floors, but the leaning tower got w____ as the tower grew. It took about 180 years to finish the tower. Today, the leaning tower has eight f____  It is 54.5 meters t____. And it leans almost 4 meters to one s____ . The tower is also sinking(下沉) into the g ____ on which it was built. Every year, the tower leans a____ 1.7 cm.