Réponse :

1. Electric cars have been greatly improved since they were created.

2. Developed countries have conducted many  green actions since the beginning of the 21st century.

3.Our school has adopted a greener policy for a while now, and it has been very positive.

4. The global surface temperature has often  varied since 1980.

5. Sea levels have risen constantly for the past  50 years.​

Voila, j'espere que sa t'aide si il y a un autre devoir que tu a besion de faire dit moi.

Réponse : 1 ) since

2 ) for

3 ) since

4 ) since

5 ) for

Explications :