Is it also possible that the line intersects the curve at one point?

Question

I am looking at the Green theorem:

$$\text{ Let S be a simple closed curve of the plane xy,}\\ \text{such that a line that is parallel to each of the axes intersects the curve S at , at most, two points. } $$

Does this mean that the line should intersect the curve at no point or two points?

Or is it also possible that the line intersects the curve at one point?

Answer 1

One point is also possible. The curve could be a circle, and a horizontal line through the bottom-most point intersects it in one point, and that's fine.