Cambridge 模考二的題目 - 英檢

想請教板上的各位，在下左思右想有點卡住。

模考二 閱讀第二題第二段

The Coriolis force itself is caused by the fact that the Earth rotates
on its axis once per day, and hence all points on the planet have
the same rotational velocity; that is, they take one whole day to complete
a rotational circle. However, since a complete rotation around the
Earth is shorter the further one is away from the equator,
different points on the Earth travel at different speeds depending on
degree of latitude. For example, a point on the equator travels the
whole distance around the sphere (about 40,000 kilometers),
whereas a point near the poles will travel a much shorter distance.
Therefore, we can say that the linear speed of a point depends
on its latitude above or below the equator.
Thus the actual linear speed of a point on the surface is faster
the nearer that point is to the equator.

題目問：
We can infer that rotation velocity is
a) the same as speed in kph
b) different at different latitudes
c) the same as different latitudes
d) dependent on latitude

答案是C，我看了好久還是搞不懂到底速度和緯度的關係是怎樣，
已經轉了很久，貼上來看看有沒有人可以給一點靈光一閃，多謝！


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