I think flute = the flute is the most difficult instrument to learn among instruments I learned. The reason I thought that the flute was the hardest is because there are too many buttons on the flute. Also, making sound is extremely tough. Especially, fixing my lips = lip movement is hard. For these reasons, flute = the flute is a difficult instrument to learn.

I suppose it is really hard to learn the flute. But good job for being able to play it. Thank you for doing your homework!