CEFR Level
A toy or instrument with mirrors and colored pieces that create changing patterns when rotated; also used metaphorically for a constantly changing sequence of patterns or elements.
"The city lights turned into a kaleidoscope of colors as the festival began."
A species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.
"Wolves are a keystone species that regulate prey populations."
a small bird with bright blue and orange feathers that catches fish by diving into water
"The colorful kingfisher dove into the pond to catch a fish."
The rank or dignity of a knight, or the ceremony of conferring knighthood.
"He was honored with knighthood for his contributions to science."