题目内容：
Why does the author cite the sea somewhere near Japan?
A．To show that the sea in some places is very dee B．To show that the sea in some places is very shallo
C．To show that its depth is 9 kilometers greater than the height of the highest mountai
D．To show that its depth is 11 kilometers greater than the height of the highest mountai
参考答案：
答案解析：