Paula is training for a marathon. When she runs, her heart beats faster than it does when she is resting. Complete the sentences, using words from the box.

blood,                 breathe,            carbon dioxide,            glucose,               heat,           nitrogen,         oxygen,           respire

         
When she is running, Paula‘s muscle activity increases. To do this, her muscle cells

(A) at a faster rate to give her more energy. Her muscles need to

be supplied with (B) and (C)

more quickly. Her heart beats faster to increase the flow of (D)

which carries the products (E) and

(F) away from her muscles.

Answers need to be in this order: (A), (B), (C), (D), (E), (F).. Single line tex