Teacher:In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Teacher: Now, understand the problem? Solve this instance: A crystal is a solid whose molecules ( or atoms ) are arranged in a repeating pattern .
Student:
A crystal or crystalline solid is a solid material whose constituents ( such as atoms , molecules , or ions ) are arranged in a highly ordered microscopic structure , forming a crystal lattice that extends in all directions .