The diagram shows an alveolus. blood from alvoolus
blood to alveolus
(4)
AIR
blood capillary
(a)
© Label structure M on the diagram above
(1) Name gas Y shown on the diagram above,
(h) Explain how gas X passes from the alvoolus into the blood capillary
121
(2)
(1)

$100. 125 x 0.20 = 25125 - 25 = $100

only b 

It depends on the surface of the levels. the rougher the surface, the greater is the frictional force. for rougher surfaces, you would need to exert greater force to move the object. the concept is that, you must overcome the frictional force in order to bring the object into motion. this is the reason why we add lubricants to the joints so they could easily move. this answer was on