Problem: Draw the trees for the following sentences, which contain recursively embedded CPs:
a. Socrates proved that Beckham plays soccer.
b. Plato asked whether Socrates proved that Beckham plays soccer.
c. Aristotle knew Plato asked whether Socrates proved that Beckham plays soccer.
d. Descartes thought that Aristotle knew Plato asked whether Socrates proved that Beckham plays soccer.