Amajor chamge in the evolutionary lineage leading to the chordates was the

Now bold Robin Hood to the north would go,
With valour and mickle might;
With sword by his side, which oft had been try’d,
To fight and recover his right.

The first that he met was a jolly stout Scot,
His servant he said he would be;
No quoth Robin Hood, it cannot be good.
For thou wilt prove false unto me.

Thou hast not been true to sire or cuz:
Nay marry, the Scot he said;
As true as your heart, I never will part,
Good master be not afraid.

But e’er I employ you, said bold Robin hood,
With you I must have a bout;
The Scotchman reply’d, let the battle be try’d,
For I know I will beat you out.

Thus saying, the contest did quickly begin,
Which lasted two hours and more;
The blows Sawney gave bold Robin so brave,
The battle soon made him give o’er.

Have mercy, thou Scotchman, bold Robin Hood cry’d,
Full dearly this boon have I bought;
We will both agree, and my man you shall be,
For a stouter I never have fought.

Then Sawney consented with Robin to go,
To be of his bowmen so gay;
Thus ended the fight, and with mickle delight
To Sherwood they hasted away.

Source: “Robin Hood and the Scotchman.” The Robin Hood Garlands and Ballads. Ed. John Mathew Gutch, William Hone, Francis Douce, and Edward Francis Rimbault. London: John Russell Smith and Joseph Lilly, 1750. 392-93. Google Books. Web. 24 June 2011.

What is the structure of this poem?

the electromagnetic energy from the sun arrives in the form of visible and invisible light.

this is more of a statement than a question. is there answers to go along with this, or is it opinion based?