Ecosystem that is not considered self sustaining?

What organ is the first to receive nutrients that have been absorbed from the digestive tract?

How do you think earths interior affects what is happening on the surface? 2. how do fossils support the continental drift hypothesis? 3. how does sea- floor spreading support the hypothesis of continental drift? 4.what do scientists observe when they studied the magnetic fields of rocks on the sides of mid-ocean ridges? 5. what is a tectonic plate ? 6. explain mantle convection 7.how can movements of the continents affect earths climate? 8. what occurs during drifting?

One reason scientists are trying to develop fuel sources from corn and sugar is because these sources are renewable fossil fuels are being depleted these crops can be widely grown all of the above