Bonjour,

Réponse :

a. Carbon dioxide and methane are the mostimportant ones.

→ greenhouse gases ( gaz à effet de serre )

b. A mass of ice and snow that permanently covers a large area of land.

→ ice cap ( calotte glacière )

c. The very cold area around the North Pole.

→ Arctic

d. Causing damage or injury to somebody or something

→ harmful ( nuisible; néfaste; nocif )

e. Calculated by adding quantities together andthen dividing by the number of quantities.

→ mean / average  ( moyenne )