sub-level sub-light sub-machine sub-machine gun sub-machine guns sub-mariner sub-menu sub-micron sub-modules sub-national sub-national governments sub-national level sub-network sub-networks sub-objectives sub-office sub-optimal sub-option sub-options sub-orbital sub-page sub-pages sub-par sub-paragraph sub-paragraphs sub-pixel sub-plot sub-populations sub-prefect sub-prefecture sub-prefectures sub-prime sub-prime mortgage sub-process sub-processes sub-processors sub-program sub-programme sub-programmes sub-programs sub-projects sub-questions sub-range sub-region sub-regional sub-regions sub-routine sub-rule sub-saharan sub-saharan africa sub-saharan africa and south sub-saharan africa has sub-saharan african countries sub-saharan africans sub-saharan countries sub-sample sub-samples sub-sampling sub-sea sub-section sub-sections sub-sector sub-sectors sub-sequence sub-series sub-set sub-sets sub-specialties sub-specialty sub-standard sub-station sub-stations sub-step sub-suppliers sub-surface sub-system sub-systems sub-tasks sub-theme sub-themes sub-threshold sub-title sub-titles sub-topic sub-topics sub-total sub-tropical sub-tropical climate sub-trust sub-type sub-unit sub-units sub-website sub-woofer sub-zero sub-zero temperatures sub-zones suba subacute