Explosives

Questions:

How long does my firearm/shot gun/explosive certificate last for?
How much does it cost for the grant / renewal / variation of a firearm / shotgun / explosive certificate?
There is a man who rents a garage next to mine and I think he has some explosives in there, who do I tell?

What are the rules in relation to single and double yellow lines?

For police non-emergencies dial 101