问题
填空题
已知圆锥的底面半径为4，母线长为6，则它的侧面积是______．（不取近似值）
答案
依题意知母线长=6，底面半径r=4，
则由圆锥的侧面积公式得S=πrl=π×4×6=24π．
故答案为：24π．
搜题请搜索小程序“爱下问搜题”
已知圆锥的底面半径为4，母线长为6，则它的侧面积是______．（不取近似值）
依题意知母线长=6，底面半径r=4，
则由圆锥的侧面积公式得S=πrl=π×4×6=24π．
故答案为：24π．
| 完形填空 | ||||
| The position of children in American family and society is no longer what it used to be. The_1_ family in colonial(殖民时期的)North America was mainly concerned with survival and beyond that, its own economic prosperity. Thus, children were 2 in terms of their productivity(生产能力), and they played the role of producer quite early. Until they fulfilled this role, their position in the family was one of subordination(附属). With the_3_of the society. the position of children in the family and in the society became more important. In the complex and technological society that the United States has become, each_4_must fulfill a number of personal and occupational_5_and be in contact with many other members. Therefore, viewing children as necessary members of society means that they are_6_more as people in their own fight than as those of subordination. This acceptance of children as_7 participants in the family is reflected in various laws_8_the rights of children and in the social and public welfare programs. This new_9_of children and the frequent contact between the members of society has also 10 an increasing interest in child-raising techniques. People today spend much time seeking the proper way to 11 children. Nowadays, the socialization of the child in the United States is a 12 transaction(事务)between parent and child 13 a one-way, parent-to-child training 14 . As a consequence, socializing children and 15 with them over a long period of time is for parents a mixture of pleasure, satisfaction, and problems. | ||||
|