501 Critical Reading Questions

c
is the correct 
answer.
421.
c.
In line 33, the author compares surfing to 
slid[ing] down a hill
.
But unlike a six-foot hill, a surfer can slide down a six-foot wave
for more than a quarter of a mile without ever reaching the bot-
tom. The author explains that this is possible because the water
that composes the wave is, like a hill, standing still 
and new water
is rising into the wave as fast as the wave travels, 
preventing the
surfer from reaching the bottom (lines 41–43). So while it looks
like a surfer is sliding along moving water, he or she is actually
stationary on a wave as it moves through the water. That’s the
secret
.
422.