青少年应该知道偶尔自慰是正常的生理现象。

Teenagers should know that occasionally ___masturbating is a normal physical phenomenon.

那个演员沉迷于自我陶醉，整天在社交媒体上炫耀自己的成就。

The actor was ___indulging his vanity by constantly showing off his achievements on social media.