在“研究匀变速直线运动”的实验中，打点计时器使用的交流电源的频率为50Hz，记录小车运动的纸带如图所示，在纸带上选择5个计数点O、A、B、C、D，各点到O点的距离如图所示．

根据学过的知识可以求出小车在B点的速度v_B为____ m/s；BD间的平均速度为____ m/s；小车运动的加速度为____ m/s²（结果均保留二位有效数字）

国民党在西安事变的和平解决中起了主要作用。

错误：____     改为：____ 

读课文《陈太丘与友期》，面对友人“过中不至”竟还“对子骂父”，元方以“____”和“ ____”来回击。（用原文中词语回答）

从方框中选出合适的词补全文章

    BBC is one of the most famous radio____  in the world．It has its own offices in London and in many other parts of the country，even in the____  countries． 

    People can find out all the BBC programmes in the BBC'S magazine Radio Times．The magazine has much more readers than any

____ magazine in Britain．BBC has a lot of radio channels(频道)and TV channels．There are all kinds of____ on them．Some are for parents，and some are for____ ．Some are for workers and farmers，and some are for teachers and students．Some give main news and some give music or sports．You can choose what you like to listen to or to watch