Good bye,lucy 是祈使句吗?

lucy,you clean the window.这是祈使句吗?为什么 rain stops,good bye是什么歌 是say good-bye还是 say goodbye good bye bye bye tonight是什么意思? Good-bye; Goodbye; Good bye这三种都对吗? goodbye中间有连字符吗?是goodbye还是good-bye, 英语—祈使句1.什么是祈使句?2.举几个例子（祈使句）3.It is a good idea to do 是祈使句吗? Long Kiss Good Bye Good-bye to those see.good.Bye She says Good-bye stay good bye