| 1. | The olympic games take place once every four years
10奥林匹克运动会每4年举行一次。 |
| 2. | They come only once every four years
这个盛会每四年才举办一次。 |
| 3. | It was he who decided to hold the olympic games once every four years
是他决定每四年举办一次奥运会。 |
| 4. | February has twenty - nine days once every four years , and that year is called leap year
二月份每4年有一次为29天，那一年被称为闰年。 |
| 5. | Article 11 ( evaluation period ) the teaching achievement prizes at the municipal level shall be awarded once every four years
第十一条（评审周期）市级教学成果奖每4年评审1次。 |
| 6. | B : once every four years , the greatest athletes from all over the world gather together to take part in the olympic games
每隔四年，世界上最优秀的运动员都从四面八方汇集到一起参加奥林匹克盛会。 |
| 7. | Intensifying the problem is the slow reproduction rate of the reptiles . on average , female tuatara mate once every four years , and eggs take between 11 and 16 months to hatch
更糟的是，这种动物繁殖率很低。平均来说，雌性每4年才交配一次，而卵需要11 - 16个月时间孵化。 |
| 8. | O refers to the anomalous increase in sea surface temperatures from the west coasts of peru and ecuador to the central equatorial pacific . this phenomenon occurs irregularly but on average recurs once every four years and usually lasts for 6 to 18 months after its onset
厄尔尼诺是指从秘鲁和厄瓜多尔西岸至赤道太平洋中部海水持续偏暖，其出现周期不规则，平均约4年出现一次，一般持续6至18个月。 |
