UK on Syria: "Frankly, my dear, I don't give a damn"

can you name your guesses?

Either they (Assad) have hidden all those materials to unknown places or others have got/stolen it.

This may be true. But my question is about the delivery systems: missiles, planes, long-range heavy artillery. If you think the opponents of Assad are also using chemical weapons - how would they be using them?

I've no deeper knowledge about the how and where al-Qaeda and its supporters are trained or from where they exactly get their support.

My guess is Qatar and the Saudis. But that is irrelevant to the question of how people with AK47 and some old Soviet tanks can use chemical weapons. For Assad's army with missiles, fighter jets and heavy artillery it is pretty clear.