Choose the correct option a, b, c or d to complete each space.

Kevin teaches (6)................ at a high school. He enjoys his teaching very much, and he always feels very (7)............. and proud when he is standing on the teaching (8).............. .Some of his ex-classmates have just offered him a chance (9)................ them in a new company (10)................. computer software  for businesses. Everyone thinks that it (11).............. very well. Kevin will (12)...............earn more money than he (13)................  at the high school. The new company is (14)................, and the money may be very good in deed. (15)...............  Kevin can hardly quit his teaching. job! He loves it.

• A. 
  mathematic
• B. 
  mathematics
• C. 
  mathematical
• D. 
  mathematician