"about math, research papers, science"

"拿着剑的天使，黑色翅膀"

"老虎是飞行员"

"Astronaut with a comet trail"

"Ghostly figure in a mirror"

"Astronaut with a space probe"

"Astronaut with a satellite"

"Wizard with a spellbook"

"Haunted castle"

"Ghostly lantern"

"Haunted graveyard"

"Sorcerer with a magical aura"

"Space marine with armor"