The place where a channel moves from along one bank of the river over to the other bank of the river is called a（）.

The ocean bottom that extends from the shoreline out to an area where there is a marked change in slope to a greater depth is the（）.

A.abyssal plain
B.continental shelf
C.borderland
D.offshore terrace

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The length of a wave is the length（）.

A.of the wave's crest
B.of the wave's trough
C.measured from crest to trough
D.measured from crest to crest

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