Once every three years

三年一次───Once every three years

The king had a fleet of trading ships at sea along with the ships of Hiram. Once every three years it returned, carrying gold, silver and ivory, and apes and baboons.───王有他施船只与希兰的船只一同航海，三年一次，装载金银，象牙，猿猴，孔雀回来。

George Bush's administration has cut family visits by Cuban-Americans, from once a year to once every three years, and has been zealous in enforcing a ban on travel to the island by other Americans.───布什行政当局将古巴裔美国人前往古巴旅游的次数从每年一次削减为每三年一次，并且不遗余力地强化一项禁令，即禁止其他美国人前往古巴旅游。

Once every three years it returned, carrying gold, silver and ivory, and apes and baboons.───三年一次装载金，银，象牙，猿猴，孔雀回来。

All directors retire from office by rotation and are subject to re-election at an annual general meeting at least once every three years .───所有董事均会最少每三年轮流退任及在下届股东周年大会上重选。

The forging routine review shall be made at least once every three years.───前项定期检讨，每三年至少应办理一次。

The number of females who reported that they had dental checkup less frequent than once every three years was 0.───报称少于每三年检查牙一次的女性人数是0。