Sagot :
Réponse:
a. how much time have they lived in England?
b. When did Marie curie discover radium ?
c. Since when have you known her ?
Réponse :
A. How long have they lived in England for?
B. How long ago did Marie Curie discovered radium?
C. How long have you known her?
Explications :
Avec perfect tense et for c'est: How long .... for?
Pour ago ce sera How long ago ...?
Pour perfect tense et since c'est How long ....?