___ causes people to fall in love remains one of the most basic human mysteries.
Love is an emotion that can not be ___
A). Defined easy
B). An easy definition
C). Easily defined
D). Defining Easily
These were in my 2000 practice questions. No matter how intrigued you are to analyse the content of the sentence, try very hard not to. Stick to the structure and make your choice. You will run out of time otherwise if you think about it too long. But besides the point, If you do insist on pondering some more about this four-letter word, I have no suggestion :) Have a great weekend...