According to the passage, destruction caused by high waves occurs （）.

单项选择题According to the passage, which of the following is TRUE（）

A．The deeper the sea, the stronger the waves.
B．The sea is always calm at a great depth.
C．Huge waves start from the depth of sea.
D．Shallow waters will not be affected by big waves.

单项选择题From the second paragraph we know that high waves striking the shore are （）.

A．gradually reduced
B．difficult to predict
C．still very powerful
D．sometimes quite weak