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It has periodic structures in both space and time .

它在空间和时间上都有周期性的结构。

The asia-pacific region can expect varyag to make periodic port calls in coming years .

亚太地区期望瓦良格号在未来的几年中进行港口停靠这种定期的访问。

The dollar suffered periodic bouts of weakness before .

美元之前也经历过周期性的疲软。

Be realistic and don 't forget periodic expenses like vehicle maintenance and gifts .

现实但不要忘记诸如汽车维护和礼物等周期性的费用。

Sudan has suffered periodic bouts of unrest .

苏丹已经遭受了周期性的暴动。