THE HIGHER THE CONTENT OF CARBON DIOXIDE IN THE AIR, _____________...
12. The higher the content of carbon dioxide in the air, _______________
A. more heat it retains
B. it retains mere heat
C. the more it retains heat
D. the more heat it retains
12. The higher the content of carbon dioxide in the air, _______________
A. more heat it retains
B. it retains mere heat
C. the more it retains heat
D. the more heat it retains