Question

These are an important source of fast short term energy

Answer 1

The correct answer is carbohydrates because this fat can perdus both short and fast energy.
     Hope this helps 

Answer 2

GLUCOSE is an important source of fast, short term energy.
When energy is needed to carry out an intensive work that will last about two minutes, ATP can be generated form glucose via anaerobic process which is called anaerobic glycolysis. This process produces two molecules of ATP and two molecules of pyruvate  from one molecule of glucose. The ATP produce is used to carry out the short term work.