"School (starts) at 8 o'clock in the morning"中 为什么“start”要加S?

School starts at nine o'clock. school starts at nine ten否定句 School starts at eight o'clock改一般疑问句 The school day starts at eight every day The school bay starts at eight every morning是什么意思 School starts at nine o'clock.（改为一般疑问句） School starts at nine o'clock变一般疑问句 school starts at nine o'clock什么意思 School starts at eight thirty.改为同义句 School starts at eight thirty.（改为同义句） At around eight o'clock,l go to school school starts at nine o'clock. School starts (at eight) every morning就括号部分提问——school start every morning In our school,school _____(is,start,starts,does) at 7:30. Our school starts at eight o'clock.对at eight o'clock提问 starts at and school four o'clock nine ends at连成句 school starts at 7:40 in our country 对at 7:40提问 School starts at( )and ends at( ).we have( )lessons in the moring and( )in the afternoon. Our school starts at 7：40,and （f ）at 4：30.