Sentence:  <u>1. Corollary</u>: <WSD>ZF</WSD> is not finitely axiomatizable. / <u>2. Corollary</u>: <WSD>ZF</WSD> is reflexive (i.e. the consistency of every finite subtheory of <WSD>ZF</WSD> can be proved within <WSD>ZF</WSD>). 
Meaning of the word marked with <WSD> tags:  Zermelo-Fraenkel set theory, without the axiom of choice.