!! Warning: This hanjie is a linea, it is only logical with the constraint that the picture consists of a single curved line, thus each black cell has exactly two of its four nearby cell blacks (except the two ends) !!

Here is what can enlighten you.

Regarding the technics, here are the main things to know for now:
We can't have any 2x2 square nor any "T". Then, edge-logic can be used easier.
Moreover, when we have a turn, we can place cross in the angle. When we have a segment, we can place cross along the line (except in the extremities).
I add that any area which is isolated from the rest by cross is necessarily empty.

Difficulty : ***

Tested, logical (as a linea).
I can propose you two different ways (if you are interested):
- Without trick: Apply edge-logic on columns C1-2 and use the fact that any isolated area is empty if there is a black square outiside.
- With tricks: Notice that one end of the already placed cells of the 14 (and the 15) matchs with the 3 (and the 2). Then place the 14 (and the 15).
Good blackenage.