The water of this river is muddy.

This shape is a parallelogram.

He is working round the clock.

My four treasures of the study are a fountain pen, a pencil, an eraser, and a ruler.

He is doing squats to train his quadriceps femoris muscle.

I saw a cackling goose in the park.

Please calculate the quartiles of this data set.

This regular tetrahedron is composed of equilateral triangles on all sides.

He is a world-renowned ichthyologist.

I am studying a foreign language.