Determine the text structure: On the river banks of the Nile River, home to some crocodiles, there are many kinds of birds, sometimes called crocodile birds because they are always hopping around crocodiles. The big crocodiles and the birds are useful to each other for several reasons. The birds eat flies and leeches that they find on the crocodiles’ skin and mouths. In this way, the birds get a good mean and the crocodiles get rid of the leeches and flies. Sometimes an enemy frightens the birds who scream and fly away. As a result of the noise, the birds give the crocodiles a warning of danger.
A. sequence/order
B. comparison/contrast
C. description
D. cause/effect