1) There's a precedent to quote.
有例可援。
2) have a precedent to go by
有先例可援
3) We have a precedent to go by.
我们有先例可援。
4) To quote a precedent
先例可援
5) Usages can be quoted
通例可援
6) have no precedent to go by
无先例可援
补充资料：有例可援
1.有成例可以援引。
说明：补充资料仅用于学习参考，请勿用于其它任何用途。
参考词条