自然

nature; natural world; spontaneity; naturalness; naturally; natch; suitably; spontaneously; au naturel; of course; as a matter of course; at ease; free from affectation; natural; crude; physical; unforced; spontaneous; unaffected; artless

规则

rule; regulation; law; weak; methodology; code; dictate; canon; regular; systematic; rolling; by the rules; according to the rules