问题 单项选择题

下列关于物体是否可以看做质点的说法正确的有()

A.研究奥运游泳冠军叶诗文的游泳技术时,叶诗文不能看成质点

B.研究飞行中直升飞机上的螺旋桨的转动情况时,直升飞机可以看做质点

C.观察航空母舰上的舰载飞机起飞时,可以把航空母舰看做质点

D.在作战地图上确定航空母舰的准确位置时,可以把航空母舰看做质点

答案

参考答案:D

解析:当物体的形状、大小对所研究的问题没有影响时,我们就可以把它看成质点,根据把物体看成质点的条件来判断即可.解:A、研究奥运游泳冠军叶诗文的游泳技术时,是有不同的动作的,所以此时的人不能看成是质点,所以A正确;B、研究直升飞机螺旋桨的转动情况时,不可以把直升飞机看作质点,否则就无转动可言,所以B错误;C、航空母舰的大小不能忽略;故不能看作质点;故C错误;D、在作战地图上确定航空母舰的准确位置时,可以把航空母舰看做质点;故D正确;故选:D

多项选择题 案例分析题
阅读理解

Every culture in the world has marriage and wedding ceremonies . Usually marriages are between one woman(the bride) and one man ( the groom). However, in other parts of the world a man may have several wives, or, as in some areas of India, a wife may have more than one husband..

There are also many different kinds of wedding ceremonies practiced around the world. These ceremonies can be very short and simple, or very long and complicated.

One of the largest and most expensive wedding ceremonies in recent times was held in Dubai in 1981. The couple tying the knot at this wedding were the son of Sheik ( a male Arab ruler) Rashid Bin Saeed Al Maktoum and Princess Salama. The wedding ceremony took seven days and cost $44 million. It was held in a large building which was specially built for the ceremony and looked like a stadium. The bride and groom needed a large place for their wedding because more than 20,000 guests were invited.

The reasons why a man and woman get married also vary. Sometimes they marry because they are in love, sometimes they marry because someone they meet through a matchmaker, and sometimes they marry because their parents tell them that they must marry.

One unusual example of an arranged marrige took place in Bangladesh in 1986.  The groom was an eleven-month-old boy and the bride was a three-month-old girl. They were the youngest married couple ever.

The parents of the bride and groom arranged the marriage as a way of ending a fight between the two families who had been arguing over a farm for twenty years. Both families thought they owned the farm, but no one knew exactly . The fight ended for good when the young boy married the young girl. By arranging this marriage, neither famlily was forced to lose face. The two families agreed to give the farm to the young people.

小题1:What is the best title for this passage?

A.An Unusual Wedding Tradition

B.A Short History of Marriage

C.Common Western Wedding Trations.

D.Interesting Wedding Around the World小题2:Who got married in the large Wedding Ceremony described in the passage?

A. a farmer and a neighbor             B. the son of a sheik and a princess

B. a king and a queen                 D. two babies.

小题3:Why was the wedding ceremony in Dubai held in a building like a stadium?

A. The ceremony was very long       

B. The groom loved to play sports.

C, Many people came to the wedding.  

D. People in Dubai usually get married in stadium.

小题4:Why did the families in Bangladesh make their children get married?

A.The children were in love

B.The families wanted to end the fight

C.The families wanted to buy a farm.

D.The bride’s family wanted to sell their farm.小题5: What was strange about the wedding in Bangladesh ?

A.The bride and groom were young.

B.The wedding was on a farm

C. It was an arranged marriage.

D.More than 20,000 guests came to the wedding