over a period of ... |
に渡り [にわたり] /(exp) throughout/over a period of .../over a span of .../ ------- に亘って [にわたって] /(exp) throughout/over a period of .../over a span of .../ ------- に渡って [にわたって] /(exp) throughout/over a period of .../over a span of .../ ------- に亘り [にわたり] /(exp) throughout/over a period of .../over a span of .../ |