He is writing a letter.

He waved his hand.

The precipitation in this area is 500 millimeters on average annually.

Due to this chemical reaction, the substance will precipitate.

I went to see a movie with my friend.

He participated in the anti-Japanese movement.

This medicine has a delayed effect, so you may not feel the effect immediately.

His project reflects his ingenuity.

It is important for men to regularly clean smegma.

Geologists believe that this area was formed by a graben.