The third argument (0) is the zero-based index of the directory that you want to create the group in if it doesn't exist.

第三个参数（0）是目录的基于零的索引，如果某个组不存在，则会在目录中创建这个组。

youdao

IPD, an information group, calculates an index of global commercial-property returns.

房地产信息机构IPD预测全球商业地产收益指数。

youdao

Jeremy Grantham of GMO, a fund-management group, has compiled an equally weighted index of 33 commodities.

GMO公司(一个基金管理公司)的杰里米·格兰瑟姆编制了一张包括33种商品的等加权指数。

youdao

After rising steadily for more than a year, the index of leading economic indicators actually slipped by .1 percent in April, according to a private research group.

VOA: standard.2010.05.20

The index, part of the group's annual State of the World's Mothers report, is intended to illustrate the link between maternal and child well-being.

CNN: Best place in the world to be a mother is...

Soon after the column was published I got a scolding letter from John Bogle, founder of Vanguard Group and patron saint of cheap index funds.

FORBES: How Many Funds Should You Own?

On Sunday, a statement issued by the Frankfurt-based lender called the latest charges "regrettable" and said it "sincerely regrets the impact on the Kospi market of an index arbitrage position unwind involving a small number of Deutsche Bank Group employees".

BBC: Deutsche Bank charged in South Korea over stock rout