How do you unlock more mission on the 39clues?

What is a peditration? What are some character traits for Kevin Quinlan in the book Stargirl? Can a mule urinate while walking? What are the examples of formal logic? What is Permanent Campaign? What must scientists look for in their experiment or their data to make sure it is accurate? What is u.p.s in computer and What is its work? If you are under 16 and your parents are really strict how do you tell them you are pregnant? What are some adjectives that describe a grape and begin with the letter P? How do you replace the blower resistor on a 2000 Olds Intrigue? What factors do 3 and 15 have in common? How old was Henry's first wife when she died? How do you register more than one account in access online? How come you can't bring up the cheats for oblivion? What is the answer for write an expression for the calculation subtract 10 divided into fifths from 20 divided in half? How many nominated people are competing in the coming UK election? What Does it mean to reincarnated as a little girl in a dream? What is the difference between apples and oranges? Is there a way you could audition for the Lightning Thief movie if there is still available people? When do surpluses occur?

How do you unlock more mission on the 39clues?