Review this list of words and context sentences to find the word that matches the definition below.
        
        Most important; main; leading
        
challenge  (chălĭnj) -noun
  - Ginny enjoys rock climbing. It’s a difficult challenge, but she feels very proud after making a climb.
 
  - Kris looked out at the tall piles of snow he had to shovel. “This will be quite a challenge,” he sighed.
 
dependent  (dĭ-pĕndənt) -adjective
  - Some animals can take care of themselves as soon as they are born, but human babies are dependent upon their parents for years.
 
  - Jayden's mother said to him, “You are too dependent on me to drive you places. You need to walk or ride your bike more often.”
 
fertile  (fûrtl) -adjective
  - Because the soil is so fertile, Iowa has many farms.
 
  - Our pet hamsters were so fertile that we ended up selling many baby hamsters back to the pet store.
 
peculiar  (pĭ-kylyər) -adjective
  - Jack didn’t know why people were giving him peculiar looks until he realized there was a food stain on his shirt.
 
  - My brother thinks my chip-and-pickle sandwiches are peculiar, but I don’t think they’re as strange as the peanut-butter-and-tuna sandwiches he eats.
 
preference  (prĕfər-əns) -noun
  - There are Chinese, Italian, and Indian restaurants nearby. What’s your preference for dinner tonight?
 
  - What's your movie preference for tonight: a comedy or an action movie?
 
principal  (prĭnsə-pəl) -adjective
  - The principal cause of most success is hard work, not luck or talent.
 
  - The queen of England has no real power. The principal leader of England is the prime minister.
 
solitary  (sŏlĭ-tĕr′ē) -adjective
  - After taking a solitary vacation in a cabin for two weeks, Oscar was ready to return to the company of other human beings.
 
  - In a mood to be by herself, Emma looked forward to spending the evening in such solitary activities as reading and taking a long bubble bath.
 
suitable  (stə-bəl) -adjective
  - Katy asked her friends if a denim skirt was suitable for the school dance, or if she had to wear a more formal dress.
 
  - Because the prices and food are so good, the team decided that the Red Lion Inn would be suitable for its annual banquet.
 
surplus  (sûrplŭs) -adjective
  - More and more restaurants are donating their surplus food to homeless people.
 
  - The Changs had more kitchen supplies than they needed, so they gave their surplus pots and pans to their son, who had just gotten his own apartment.
 
transform  (trăns-fôrm) -verb
  - My sister plans to transform our messy attic into her own bedroom.
 
  - The magician seemed to transform a chicken’s egg into an egg the size of a basketball.