In some societies people want children for what might be called familial reasons: to extend the family line or the family name, to propitiate the ancestors; to enable the proper functioning of religious rituals involving the family. Such reasons may seem thin in the modern, secularized society but they have been and are powerful indeed in other places.  
In addition, one class of family reasons shares a border with the following category, namely, having children in order to maintain or improve a marriage: to hold the husband or occupy the wife; to repair or rejuvenate the marriage; to increase the number of children on the assumption that family happiness lies that way. The point is underlined by its converse: in some societies the failure to bear children (or males) is a threat to the marriage and a ready cause for divorce.  
Beyond all that is the profound significance of children to the very institution of the family itself. To many people, husband and wife alone do not seem a proper family —they need children to enrich the circle, to validate its family character, to gather the redemptive influence of offspring. Children need the family, but the family seems also to need children, as the social institution uniquely available, at least in principle, for security, comfort, assurance, and direction in a changing, often hostile, world. To most people, such a home base, in the literal sense, needs more than one person for sustenance and in generational extension.  
答案：Part B 参考译文 
在某些社会中，人们希望拥有孩子是出于所谓的家庭原因：传宗接代，光宗耀祖，讨好祖辈，使那些涉及到家庭的宗教仪式得以正常进行。此类原因在现代世俗化的社会中似显苍白，但它们在其他地方曾一度构成并确实仍在构成强有力的理由。  
此外，有一类家庭原因与下列类别不无共通之处，这便是：生儿育女是为了维系或改善婚姻：能拴住丈夫或者使妻子不致于无所事事；修复或重振婚姻；多子多孙，以为家庭幸福惟有此法。这一点更可以由其反 面得到昭示：在某些社会中，无法生儿育女（或无法生育男孩）对婚姻而言是一种威胁，还可作为离婚的现成借口。  
后代对于家庭这一体制本身所具有的深远意义远非如此。对许多人来说，夫妻两人尚不足以构成一个真正意义上的家庭——夫妻需要孩子来丰富其两人小天地，赋予该小天地以真正意义上的家庭性质，并从子孙后代身上获取某种回报。  
孩子需要家庭，但家庭似乎也需要孩子。家庭作为一种社会机构，以其特有的方式，至少从原则上说，可在一个变幻莫测、常常是充满敌意的世界中让人从中获取某种安全、慰藉、保障，以及价值取向。