photosynthesis-the ability for a plant to make it's own food using the heat energy of the sun.. Photosynthesis helps us survive because it is a way for plants, grass, and trees to produce it's own...
It keeps the eyes moist which keeps them healthy which lets us see properly which can help us survive.
they help us go pee
Plants provide oxygen for us to breathe, food/energy/nutrients for us to use, and shelter.
Yes for water.