I saved the draft.

An electric arc is a phenomenon where a strong current flows between electrodes.

The calculation of arcsine is a part of trigonometry.

Calculating the arctangent, which is one of the trigonometric functions, is difficult.

The calculation of arccosine is a part of trigonometry.

The calculation of the arccotangent is a part of trigonometry.

The air in this room is fresh.

What will you use this empty box for?

Looking at the bird flying high in the sky, I felt freedom.

The altitude of this airplane is 10,000 meters.