And because the focus is on the y axis, 2/k >; =2, which is k.

So the answer is: d;

Question 2: The standard equation of parabola is: y = 2px2;

The alignment equation is: y =-1/2 * p;

So the answer is: a;

Question 3: Elliptic equation: a=2, c =1;

So hyperbola: a= 1, c = 2；;

So the answer is: B.

Question 4: To tell the truth, this question is half-guessing and half-drawing. Because point P is on the left, the abscissa of the center of the inscribed circle is negative, and then we can know that it can't be the focus coordinate by drawing.

So the answer is: a;