Why did astronaut Gene Cernan struggle to complete his work assignment in space?

difficult as the spacecraft was not designed with enough handholds.

Explanation:

Cernan was tasked to do one of the first American spacewalks, which ended up being immensely difficult as the spacecraft was not designed with enough handholds.

c. are smaller than lakes. Ponds and lakes are often indistinguishable, and rules in classifying may differ per region. But ponds are relatively smaller than lakes and more shallow. Lakes are deep  enough that light cannot penetrate the bottom of the water.