“最美孝心少年”邓天芦，从3岁起就开始学习照顾生活不能自理的妈妈。多年来他一直坚持为妈妈洗衣做饭，同时还管理自家农田和菜地。这说明孝敬父母（ ）
①只要求在生活上照顾父母        ②要积极承担家庭责任
③要落实到行动上，从小事做起    ④只是公民的道德义务 

X、Y、Z、M、W为五种短周期元素。X、Y、Z是原子序数依次递增的同周期元素，且最外层电子数之和为15，X与Z可形成XZ₂分子；Y与M形成的气态化合物在标准状况下的密度为0.76g/L；W的质子数是X、Y、Z、M四种元素质子数之和的1/2。下列说法正确的是

    Rick is a good man．He makes birthday cakes in a shop．His cakes are great and have very good prices，so many people buy his cakes．He makes friends with lots of his customers(顾客)．They all like him very much．One evening．he wants to go home，but many of his old customers come in．Rick smiles(微笑)to them，“I am sorry．It is late today．If you need cakes，please come tomorrow．”One of them takes out a nice cake and says to him，“You make so many great cakes for us．This birthday cake is for you．Happy birthday, Rick．”

下列各句中，没有语病的一句是 (　　)

探月卫星的发射过程可简化如下：首先进入绕地球运行的“停泊轨道”，在该轨道的P处，通过变速，再进入“地月转移轨道”，在快要到达月球时，对卫星再次变速，卫星被月球引力“俘获”后，成为环月卫星，最终在环绕月球的“工作轨道上”绕月飞行（视为圆周运动），对月球进行探测，“工作轨道”周期为T，距月球表面的高度为h，月球半径为R，引力常量为G，忽略其他天体对探月卫星在“工作轨道”上环绕运动的影响。求：