wehavenoroomsavailiableforyou|room一定要复数吗?room一定要复数吗?单数是病句吗?wehavenoroomavailiableforyou有什么区别

　　wehavenoroomsavailiableforyou|room一定要复数吗?

　　room一定要复数吗?

　　单数是病句吗?wehavenoroomavailiableforyou

　　有什么区别