一、Soil Formation托福听力原文： NARRATOR:Listen to part of a lecture in the geology class.MALE PROFESSOR:So,we all know soil.It's important to plant growth,right?And we know that there're different types of ...

This is a preview. Log in through your library . Abstract The main goal of the study was to determine the diversity of the potential nitrogen-fixing (PNF) bacteria inhabiting agricultural (A) soils ...

A series of slowly widening fissures in southern Ethiopia once again drew the attention of scientists and authorities to one ...