In 1952 the preparatory period began.

1952年，预备工程开始了。

youdao

The preparatory period is six months.

筹建期为六个月。

youdao

This preparatory period (two or even three months, there is no strict rule) is an integral part of your sabbatical, and you must know it.

这一预备期（两个月甚至三个月，对此没有严格规定）是你假期中不可缺少的一部分，你一定要了解这点。

youdao

Hitherto some had marked the end of a two-year preparatory period, spelt out by the PA prime minister, Salam Fayyad, who set August 26th this year as the date for completion.

ECONOMIST: East Jerusalem