实验“用DIS研究机械能守恒定律”的装置如下图a所示，某组同学在一次实验中，选择DIS以图象方式显示实验的结果，所显示的图象如下图b所示。图象的横轴表示小球距D点的高度h，纵轴表示摆球的重力势能E_P、动能E_K或机械能E，图b的图象中，表示小球的重力势能E_P、动能E_K或机械能E随小球距D点的高度h变化关系的图线分别是                                                                            （    ）

我们正值朝气蓬勃的青春时代，让我们一起来开展“放飞青春”综合性学习活动吧。

       青春应立志为国。范仲淹少有大志，每以天下为己任，发奋苦读；“两弹元勋”心年轻时就立志要让中国变强盛，将自己毕生的心血奉献给了赌博的国防科研事业。

下列关于内能和热传递的说法中，正确的是(    )

阅读理解

	Chinese writer Mo Yan won the Nobel Prize in Literature in 2012. Mo, who was born in 1955 into a farmer's family in Gaomi County in Shandong Province, is the first Chinese national to win the Nobel Prize in Literature. In his early years, life was not easy and he experienced hunger（饥饿）. These things have influenced Mo Yan's later writings.
	60-year-old Park Geun-hye(朴槿惠)was elected（选举）the new President of South Korea in December, 2012. She becomes the country's first female head of state and her term will last five years from 2013. “I will become a president who puts people's living before anything else,” she told the cheering Peopl in central Seoul as she accepted her win. “I will keep my premises.”
	Barack Obama (born in Hopolulu, Hawaii in 1961), who was elected the 44th President of the United States in 2008, has been elected again to a second term, fighting against Republican chllenger Mitt Romney. Obama is a graduate of Columbia University and Harvard Law School. His father was from Kenya. And his mother was born in Wichits, Kansas.

张先生采用贷款的方式用60万购买现房，其中首付20万，在20年内付清银行贷款40万及利息19万。其中的60万房价、20万首付现金及19万利息分别体现了货币的
（   ）