Perhaps as important is the relation between the existence of solutions to a competitive equilibrium and the problems of normative or welfare economics.
In a state, the liberty of one citizen is the liberty of all.
The future of coal lies in clean and efficient utilization.
记忆是一件复杂的事情，是真理的亲戚，但不是它的双胞胎。
A building should be readable like a book.