Well just prestige and you will get extra class slots! Every time you prestige you get an extra slot each time, i have 7 slots now.
Hope this answered your question!
More guns. It continues the storyline from modern warfare 2. For multiplayer, there will be more perks and killstreaks and weapons. Also for multiplayer there will be more maps.
Just kill people
you have to get kills on your friends or on wifi the more kills the more guns
The multiplayer weapons are not for competitive play and that is why you cannot equip them. In the competitive multiplayer you have to pick up weapons arround the map. In the Co-OP multiplayer however you can choose what weapons you wish to use before you start.
On Modern Warfare 2, you earn weapons for multiplayer by achieving higher ranks in multiplayer.
any weapons can be used even dual weapons
That depends, if you prestige then you are simply doing the multiplayer part of the game over again, and since your doing it over again you already have some experience, and therefor it maybe easier to unlock weapons again.
Biochemical Warfare is war using weapons of a biological or chemical nature. such as biotoxins. Anthrax bombs are a good example of bichemical weapons. To use weapons of mass distruction.
There are no golden weapons in Modern Warfare 2.
well there was more dangerous weapons in warfare 1 and less dangerous weapons in warfare now ..............
only if you have ten points on school of warfare and then dual weild is available then your allowed to bring two weapons.
Biological Warfare