充要条件

necessary and sufficient condition

to fill / to satisfy / to fulfill / to act in place of / substitute / sufficient / full

sufficient; full / to fill / to serve as; to act as / to act falsely as; to pose as

to demand / to request / to coerce

important / vital / to want / to ask for / will / going to (as future auxiliary) / may / must / (used in a comparison) must be / probably / if

(bound form) to demand; to coerce

to want; to need; to ask for / will; shall; about to / need to; should / if (same as 要是[yao4 shi5]) / (bound form) important

strip / item / article / clause (of law or treaty) / classifier for long thin things (ribbon, river, road, trousers etc)

condition / circumstances / term / factor / requirement / prerequisite / qualification / CL:個|个[ge4]

condition; circumstance; term; factor / requirement; prerequisite; qualification / situation; state; condition / CL:個|个[ge4]

item / component / classifier for events, things, clothes etc