那个健身教练嘲笑新学员是个细脖子，说他举不起杠铃。

The fitness trainer mocked the new trainee as a ___pencil-neck, saying he couldn't even lift the barbell.

别理那个书呆子，他整天只知道解数学题。

Ignore that ___pencil-neck, he only cares about solving math problems all day.