A list of words is given in a box. Use appropriate words to fill up the blanks in the following statements.
[Air, oxygen, wind, water vapour, mixture, combination, direction, road, bottles, cylinders]
(a) The ______ makes the windmill rotate.
[Air, oxygen, wind, water vapor, mixture, combination, direction, road, bottles, cylinders]
Mountaineers carry oxygen ___ with them while climbing high mountains.