It seems that the last is a later development while the first six groups show the relics of an older system.

似乎最后一个是后来建造的，而前六组是更古老时代的遗迹。

youdao

My family are moving to Canada early next year, and we're hoping to find somewhere to rent in Fairfield for the first six months while we settle in.

我们家明年初就要搬到加拿大去了，我们希望安顿下来的时候在费尔菲尔德找个地方租下来先住六个月。

youdao

For the study, 325 employees spent six months taking part in ROWE, while a control group of 334 employees continued with their normal workflow.

在这项研究中，有325名员工花了6个月的时间参加 ROWE ，而对照组的334名员工则继续以正常的流程工作。

youdao

Thirty people managed to swim to shore, while six others are reported to have remained onboard with the smugglers,".

VOA: standard.2009.09.01

In one study,infected mothers began to take three anti-H.I.V.drugs while breastfeeding for up to six months.

VOA: special.2009.07.29

The Smithsonian was started in eighteen forty-six while James Polk was President.

VOA: special.2010.07.09

Of those 22 participants, 10 see prices up, while six see prices down, and six are neutral.

FORBES: Survey Participants Have Mixed Outlook For Gold Prices Next Week

Of those 22 participants, 13 see prices up, while six see prices down, and three are neutral.

FORBES: Major Of Survey Participant See Gold Rising Next Week

Of those 21 participants, 11 see prices up, while six see prices down, and four are neutral.

FORBES: METALS OUTLOOK: Gold Could See Potential Bounce Next Week, But Market Watchers Cautious