下列几种变异中，不能遗传的变异是(     )。

为考察高中生的性别与是否喜欢数学课程之间的关系，在我市某普通中学高中生中随机抽取200名学生，得到如下2×2列联表：

经计算K²≈6.06，根据独立性检验的基本思想，约有____ （填百分数）的把握认为“性别与喜欢数学课之间有关系”．

A

    Skin­diving is a new sport today. This sport takes you into a wonderful new world. It is like a visit to the moon. When you are under the water, it is easy for you to climb big rocks, because you are no longer heavy.

    Here, under the water, everything is blue and green. During the day, there is plenty of light. When fish swim nearby, you can catch them with your hands.

When you have tanks of oxygen on your back, you can stay in deep water for a long time. But you must be careful when you dive in deep water.

    To catch fish is one of the most interesting parts of this sport.

    What's more, there are more uses for skin­diving. You can clean ships without taking them out of water. You can get many things from the deep sea.

    Now you see that skin­diving is both useful and interesting.