A. the rocks in the upper course are less resistant
B. the volume of the river is small
C. hanging valleys join the main valley as waterfalls to cause the gorges
D. the upper course has has a steep gradient
E. the water contains chemicals which dissolve the rocks

Correct Answer:

Option D – the upper course has has a steep gradient

SEE ALSO  The roots of trees in the mangrove forest in Nigeria are aerial because?

Copyright warnings! Do not copy.