This is striaght out of the help files showing what could be re-upped before the current version.
Target type Target Destroy with Downtime Effect Supplier Can be resupplied
Zone HQ 37 1000 lb 2 hours Kills all radar for a country City building Yes
AAA factory 1 250 lb 3 hours Loads supplies for field guns City building Yes
Radar factory 1 250 lb 3 hours Loads supplies for field radar City building Yes
Ammo factory 1 250 lb 3 hours Loads supplies for ammo at fields City building Yes
Fuel refinery 1 250 lb 3 hours Loads supplies for fuel tanks at fields City building Yes
Training facility 1 250 lb 3 hours Loads supplies for barracks at fields City building Yes
City City building 1 250 lb 3 hours Loads supplies for factories and HQ City building Yes *