TANGSA
In the past At presentNo trees,
no firewoodTrees grow
thickly
Soil was carried away
Roots fix soil together
Trees were cut but none were planted.
A few can be cut and the rest are left to grow even taller.
Uses of trees
As a kind of fuel--firewood
Building materials
Homes(nest) of birds and wild animals
…
Give out oxygen & give foodPrevent wind from blowing hard
Make our world purer and more beautiful
Prevent flood and keep air wet
Provide a shade
Carbon dioxide
CO2
H2OWater
Oxygen
O2
Cn(H2O)m
Carbon hydrate
Photosynthesis (光合作用)
Give out oxygen & supply food
water
vapor
Prevent flood Keep air wet
rain
waterwaterwaterAbsorbed by roots
Evaporated( 蒸发 ) by leaves
According to the pictures below, please describe the environment around you, and point out the disasters or harm without trees!
Make full use of your imagination to put on a performanceKey: show and emphasize the importance of trees to our life.