Directions: Choose the appropriate answer from the options given below:

_______ is a deep valley with steep to straight sides.

A gorge is a deep valley with steep to almost straight sides, typically carved by rivers eroding through resistant rock over time. The key distinction from canyons is that gorges have steeper, more narrow walls. V-shaped and W-shaped describe valley cross-sections but not the steepness criterion, while canyon is broader with less steep sides. Famous examples include the Three Gorges on China's Yangtze River.