他将硬币用力按入自己的手掌心。

He pressed the coin firmly into the ___palm of his hand.

面试时，由于紧张，她的手掌心都出汗了。

Her ___palms were sweaty from nervousness during the interview.

算命先生仔细端详了我手掌上的纹路。

The fortune teller carefully examined the lines on the ___palm of my hand.