Black and white drawing of a mountain range with trees in the foreground

Chinese scroll painting of a tree on a blue background

Blue and red circle with an arrow pointing to the center of it

Painting of a man in a blue coat and red tie

Molecular model of a peptide molecule on a white background

Drawing of a metal pole with a wire attached to it

View from the top of a hill

Painting of a man in a red robe

Drawing of a trolley car on a white background