小王的时间既可以听一次经济学讲座也可以打一场网球。他选择了听讲座，打网球的价值就是（）A、听讲座的机会成本B、大于听讲座的价值C、不能与听讲座的价值相比D、等于听讲座的价值

第一步，本题考查容斥原理，用公式法解题。
第二步，设没有报名参加其中任何一场讲座的有x人。根据三集合非标准型容斥原理公式，可列方程42＋51＋88－30－2×12＝139－x，解得x＝12。（或者使用尾数法解题）

LECTURE NOTICE?March 12,2010
Dear Neighborhoods,
Nowadays,the crime among teenagers seems increasing,so we invite a famous professor,Dr．Li Zhigang from Beijing Normal University to give a lecture on the topic“Teenagers'Education at Home”．This lecture could be very helpful to us who are doubt in how to communicate with our own children,who feel difficult to control our children,who don't know how to deal with the problems our children face and so on．We will have personal discussion with the professor after the lecture if you need any help from him．
The lecture will begin at 8:00 p．m．Friday,in the Meeting Room,Building 4．One member,at least from each family,is required to attend．
Please be there on time．If you have any problem to be present,please call 54312789．
Neighborhoods'Committee

P318；生活行为改变的项目比提高健康认知项目更进一步的地方是，将与生活方式相关的行为改变确定为预期目标，包括限盐、控油、戒烟、身体活动、压力管理、体重管理以及膳食行为选择。

有意义学习的本质就是以符号为代表的新观念与学习者认知结构中原有的适当观念建立起非人为的和实质性的联系的过程，是原有观念对新观念加以同化的过程。接受学习是指学生通过教师呈现出的材料来掌握现成知识的一种学习方式。学生兴趣盎然地听科普讲座属于有意义的接受学习。故选A。