Yoshitsugu specializes in the study of broadbanded thornyhead.

His specialty is physics.

I buy fresh fish at the fish market every week.

He is conducting research on a new energy source.

He is researching about a new energy source.

He accidentally pricked his hand on a thorn.

A shrub with thorns is surrounding the garden.

The problems of this company start from the top, just like the saying 'the fish rots from the head'.

The semispinalis capitis muscle is a part of the neck muscles, helping to tilt the head backwards.

Don't stick your head out.