yes but not all attachments :)
Use every weopon once in single player mode
The Call of Duty 4 campaign is strictly single player.
There are several ways to play call of duty, if you have a device that does not connect to the internet then there are single player options. Also there is a campaign option which is single player and you do not need to be connected to internet.
go on the campaing
The Call of Duty Wikia lists the different single player levels and contains a link for detailed descriptions and is available through the related link
The Call of Duty Wikia has a complete list of the Call of Duty Black Ops weapons from the related link
yes it is for single player offline and multiplayer online if by classic you mean Call of Duty 3 see related link
You cant get one in single player but you can get one in multi player
No, Call of Duty: Modern Warfare 3 for Wii is single player.
Call of Duty Reflex Edition includes all the features of both the single and multi-player modes of Call of Duty 4, except for the fact that there is no squad-mate mode on Call of Duty 4.
check youtube for the INTEL locations
complete the campaign (cod5)