乃是

[nǎi shì]

• to be

例句

1. 因此，对一个从事社会活动的人来讲，培养一种嗜好和新的情趣方式，乃是至关重要的对策。
   The cultivation of a hobby and new forms of interest is therefore a policy of first importance to a public man.
2. 将在适当的时候加以说明的，乃是这一数字的来源。
   It is how this number is known that will be described in due course.
3. 我遇到她乃是上上个礼拜。
   It was the week before last that I met her.