5.39.217.76, M" r# G, v) i a- B
$ j9 y% Z! V% ^0 `: rtvb now,tvbnow,bttvbNo, I read that when the leaves fall it released CO2 back to nature.
9 [8 l* F( U1 x! B: O' Z! n; t- O1 WI don't know its true or not.
# I5 n2 F4 U' ?+ Wtvb now,tvbnow,bttvbSweetLemon 發表於 2016-7-14 08:05 PM  A tree can absorb 13lb CO2 every year. A typical V8 car produce 220g CO2 per km. How many trees are needed? |