In order to be insured the safety of driving of train , the nation has prescribed that the frame of the train must be repaired completely every four years 为了保证列车行驶的安全性，国家规定每四年必须对车架进行一次大修。
The survey , which is done every four years , was conducted with the aim of understanding the latest drug abuse situation among teenage students 调查每四年进行一次，旨在了解学生的滥用药物情况；亦同时希望找出绝大多数中学生不被毒品引诱的防御因素。
To recognize the origins of this increasingly popular game , the iroquois now compete as a national team at the world championships , which are held every four years 为了探寻这项不断受欢迎的运动的起源，伊洛郭人现在在每四年一届的世界杯上以国家队的身份参赛。
At this time greece was grievously worn by internal and it occurred to iphitus to ask the god at delphi for deliverance from these evils . the story goes that the pythian 古代奥运会为祭祀希腊的万神之王宙斯神而设立，每四年一届，在古希腊最著名的宗教祭祀圣地奥林匹亚举行。
One of the world ' s most popular sporting events . the men ' s world cup began in 1930 . the women ' s world cup was first played in 1991 . it is held every four years 世界杯是世界上最受欢迎的运动项目之一。男子世界杯开始于1930年。女子世界杯在1991年第一次举行。世界杯每四年举行一次。
However , women were not completely excluded from competitive sports , as they had their own games , every four years as well , called the heraea , after hera , the wife of zeus 然而妇女并没有完全被排斥在体育比赛之外，她们有自己的运动会，也是每四年举行一次，叫做赫拉亚，以宙斯的妻子赫拉命名。
The association meets in a formal session once in four years to discuss regional co - operation to improve meteorological services , aiming at the protection of life and supporting social and economic development 该协会每四年召开一次，讨论区域性合作、改善气象服务等事宜；而最终目的是保障人命，支持社会发展及促进经济增长。
Set up under the auspices of the un to establish a scientific consensus on climate change , the ipcc has produced vast reports on the current state of knowledge on the subject every four years or so 由联合国发起建立的政府间气候变化专业委员会，目的是要对气候变化达成一个共识，每四年左右根据已有的研究成果，对全球气候变化提出科学的评价报告。
Every year riga hosts large international cultural festivals , the largest is the national song and folk dance festival that is held every 4 years and assembles about 30 , 000 participants and attracts tourists from around the world 每年里加都举办大型国际文化节日，其中最大的是每四年举办一次、共有三万人参与、吸引来自世界各地游客的全国歌曲及民间舞蹈节。
