You Can't!----Technically speaking you can. It's called the "Poor Man's Chronograph". Here is the link <http://redwolfairsoft.com/redwolf/airsoft/BulletDetail?bulletID=34>.
dont let them make contact with the snow or find some sort of cover for the gun.
No it depends, you need to check the rail size of your rifle, then the sort of rail that the scope can attach to. These are some standard airsoft scopes, check your gun rail size first though!
you can get airsoft grenades on certain websites. never at a retail store or something of the sort. airsoft grenades is in the midst of a heavy amount of research at the moment. don't count on finding a call of duty airsoft grenade. but you can try.
An indicator of some sort
I am not sure that KWA is an acronym of any sort. I just think it means KWA. but if your question means you wish to know about their guns, KWA manufactures some of the best and reliable electric airsoft rifles and gas blowback pistols out there
Probably a wall of some sort.
All you need is a speed-gun of some sort,to measure the speed.
Without their liver, no, not without some sort of medical technology, and perhaps not even then. Without one kidney, yes, quite easily in most cases. Without both kidneys, no, again not without some sort of medical technology (usually a kidney dialysis machine).
Without some sort of hacking device,no.
You can't without some sort of cheat device
Measure the water in a beaker of some sort.
There is no way to actually "weigh" a person without using some sort of scale.