张开to spread

刚开始at first

• 我新来乍到，一切都不熟悉。

  I have just arrived, and everything is new to me.

• 乍一看，他有五十来岁。

  At first glance, he is over 50.

• 乍一看，弄不清楚是怎么回事。

  At first glance, one cannot make out what this is.

• 乍一见面，我想不起来他是谁。

  When we met, I could not remember who he was at first.

忽然suddenly

• 乍冷乍热

  suddenly go from cold to hot