INVADERS


1.      Do you know what these expressions mean? What is their pronunciation?


biosphere

homogenization

species

natural habitats

biodiversity

hierarchy

hierarchical

invasion, invasive

menace


2.      Read the first two paragraphs and formulate the subtitle for this extract.



3.      Do you know some species that have invaded natural habitats of other species?



4.      The article deals with various degrees of menace caused by invasive species. Scan the text
and say how many levels are mentioned.



5.      Read about the levels and characterize them in your own words.