Every morning the clock rings at 6 中的ring为什么加s

Every morning the clock rings at 6 中的ring为什么加s as soon as bell rings为什么ring加s bell rings的ring为什么要加s "School (starts) at 8 o'clock in the morning"中 为什么“start”要加S The school day()(start) at eight clock every morning. 1.The desk is too h—-.2.I g-- up at 6 o‘clock every morning. The clock ( ) （wake) me up every morning. The postman comes at exactly ten o’clock every morning to de walk （ ）at 6 o‘clock in the morning 根据首字母写单词 My (a )clock rings at seven am every day. 请问while watching TV,we heard the doorbell ring.ring为什么不能加S啊? every morning at 6 o'clock 是一般现在时还是现在进行时的标志?