请问是on the door还是at the door?还有“在春节”是in the Spring Featival还是at the Spring Festival或是其它?

是knocked at the door还是knocked on the door 请问是on the door还是at the door?还有“在春节”是in the Spring Featival还是at the Spring Festival或是其它? 在门上是on the door还是in the door? 请问 ：The man knocked at the door.the door是宾语吗?这个句子中knocked at the door 是谓语,还是knocked at 是谓语,the door 做宾语 请问whose door是等于the door of which还是等于of which the door? the person at the door为什么不说the person is at the door?The book is on the desk.we are on the left.都有系动词．为什么就这个没有．还是这句话是错的? at the door和on the door的区别? 请问On the morning 和 In the morning 和 At the morning的区别?是 In the morning 还是 In morning 是At the morning 还是 a't morning While two detectives were keeping guard at the door请问这里的guard at the door是固定搭配吗? 敲门英语可以说成 knock at on the door 因为书上写 knock at (on) the door on 是可以省略么? There is some one ( )the door.是填介词at or on? at the door 是状语吗 who was knocking at the door just now?还是who knocked at the door just now? 请问窗台边是at the edge of the window还是on the edge of the window? knock at the door敲门应该是knock at the door,有时也看到有用knock on the door的,还有是不是可以直接说“knock the door呢? 关门是close the door还是 closed the door the heavy box is __,so I can't open the door,A,by the wayB,on the wayC,in the wayD,at the way knock at the door 和 knock on the door有什么区别吗详解,谢