Answer:
Sorry I can't understand anything
The definition of vestigial organs are rudimentary structures in humans
that correspond to a functional structure or organ in an ancestor.
Basically the answer is redundant organs present in an organism, which
have been functional in the organism's ancestors.
One of the many places that the students would be able to grow grass is a nutrient rich soil area.
Http://www.biocab.org/Carbon_Dioxide_CO2.html
The last one because plants move oxygen out to the atmosphere while taking in C02
