咩都冇ge cert= =

ps. oh my god!!

ps2. ........

compare & contrast the occurrance & significance the development of negative pressure in plant and animal.   (10 M)

occurrance:

animal : a reduced pressure in the relaxing atria

plant  : a pressure in the leaves during evaporation of water

significance:

animal : draw blood along the veins back to the heart

plant  : to draw the water along the stems to the leaves

我諗左呢d= =.....有冇咩意見?