— Have you seen the film called The trouble with Teenagers?

—Yes, but I don't think it is worth _______.

我国第一台磁悬浮列车自重20吨，载重量可达10吨．当满载的磁悬浮列车沿水平方向匀速运行过程中，列车在竖直方向上受到的电磁力是____ N（g取10N/kg）．制动后的磁悬浮列车，由于　____ 　也同样会继续向前运行一段距离．

关于艾弗里“肺炎双球菌转化实验”和“噬菌体侵染细菌实验”的叙述中，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．”