Q 01/05

Which river cuts the Iron Gates, the gorge that divides Serbia from Romania?

A) The Rhine

B) The Volga

C) The Danube

D) The Elbe

Answer · why

C) The Danube

The Danube: a dam built across the gorge around 1970 raised the river and drowned Ada Kaleh, a mid-stream island of Turkish houses with its own mosque...

Q 02/05

From which language does the word 'canyon' come?

A) Portuguese

B) Spanish

C) Italian

D) French

Answer · why

B) Spanish

Spanish: cañón also means a tube or pipe, the usual explanation for the gorge sense, though some dictionaries allow that it began as an older word bui...

Q 03/05

Why do deep, sheer canyons form more readily in dry regions than in wet ones?

A) Desert rivers flow much faster

B) Little rain wears the walls back

C) Wind-blown sand does the cutting

D) Deserts have more earthquakes

Answer · why

B) Little rain wears the walls back

Little rain wears the walls back: a stream fed from wetter country upstream keeps sawing downward, while the dry cliffs beside it stay steep and angul...

Q 04/05

What defines a box canyon?

A) Steep walls on three sides and one way in

B) It ends abruptly in a lake

C) It was carved by a glacier, not a river

D) A perfectly square cross-section

Answer · why

A) Steep walls on three sides and one way in

Steep walls on three sides and one way in: the town of Telluride sits in one, yet Butch Cassidy robbed his first bank there in 1889 and still got clea...

Q 05/05

What term describes a river that lies at the bottom of a deep canyon and cannot shift its course?

A) Captured

B) Entrenched

C) Meandering

D) Braided

Answer · why

B) Entrenched

Entrenched: on a floodplain a river wanders and changes course at will, but one that has cut deep into rock is walled in and can only go on cutting do...