Which techanique is recommeded for determining the odour of an unknown liquid in the laboratory?
A. Hold a test tube of the liquid under the nose and inhale the vapour
B. Transfter a feq drops of the liquid to the desk top and inhale the vapour from there
C. Use a medicine dropper to collect a small quantity of the vapour and squirt this under the nose while inhaling.
D. Use a hand to fan some of the vapour from the test tube to the nose and inhale.