Astronomy is the best science for studying planetsAstronomy is the best science for studying planets
An astronaut landed on the moon for a scientific study of the surfaceAn astronaut landed on the moon for a scientific study of the surface
There are several books on the shelf in the libraryThere are several books on the shelf in the library
Image of an open book with a key hanging over the bookImage of an open book with a key hanging over the book
Научный труд.