aquamarine (the color or the gemstone)

not necessary to; don't have to

Expresses gratitude or relief for something that happened in the past, a choice made, etc.

If only ~

It's good / okay to... / is fine

頭: head

head / counter for large animals

head (body part) / (anatomy, archaic, possibly obsolete) the fontanelle part of the skull

a head, as when counting people, or cattle or other livestock

the head as a whole / boss, leader / top part of a Chinese character / the head of a doll