Misc: Of which bird did Wordsworth write "Shall I call thee bird, or but a wandering voice?

Questions

Physiological systems that enable organisms to live in harmony with the rhythms of nature, such as the cycles of day & night & of the seasons?

Poet Robert Frost & the white mountains, both call this state home?

Process of heat treatment by what glass & certain metals & alloys are rendered less brittle & more resistant to fracture?

Few people know how to be old Who by?

Republic in southern central America, bounded on the north by Nicaragua, on the east by the Caribbean Sea, on the southeast by Panama, & on the southwest & west by the Pacific Ocean?