we neednot have worried because the train doesn't leaveworried 前要加个have 为何?doesn't leave是一般现在时啊，怎么是对过去的虚拟呢？

we didnot see him at the meeting.he () it.A.couldnot have attended B.neednot have attendedC.shouldnot have attended D.must have attended we neednot have worried because the train doesn't leaveworried 前要加个have 为何?doesn't leave是一般现在时啊，怎么是对过去的虚拟呢？ 写过去式?is[ ] are[ ] worr[ ] bug[ ] eat[ ] drinr[ ] do[ ] have[ ] learn[ ] go[ ] teach[ ] dance[ ] give[ ] live[ ] coor[ ] study[ ] 根据句意和首字母提示完成句子,每空一词1.Luckily ,he has an o—— to get an advanced study in Beijing.2.Most children can not c—— on one thing for a long time.3.The main difficulty to do the work is we have no e——.4.I'm worr 主语+be动词＋not＋动词 和主＋动词＋not是不是一样的意思?如i donot need ,i neednot,i donot have,i havenot have we we never have.we never What we already have,we have. YOU neednot to come so early every day改错 then we have english actually we have We have 英语翻译 We have only one We have a show We have great ()() girls! we have a good We have shorts in We have English是什么意思?