停止蹬车后，行驶在水平路面上的自行车仍继续向前运动一段距离，这是因为自行车具有_________，自行车最后还会停下来，这是因为它受到 __________的缘故．若路面光滑，自行车将一直做匀速直线运动，牛顿曾对此做过研究，并总结出___________定律．

In Pride and Prejudice, Jane Austen explored three kinds of motivations of marriage the middleclass people had in the second half of the 18th century. Try to make a brief discussion about them with specific examples from the novel. Make comments on Austen’s attitude towards these motivations.