Ответ:
1 Has Marry been teaching Frech since1998?
How long has Mary been teaching Frech?
She has been teaching Frech since 1998.
2 Have the children been watching TV for 2 hours?
What have they been doing for 2 hours?
The children have been watching TV for 2 hours.
3 Has Laura been playing the guitar for 4 years?
How long has she been playing the guitar?
Laura has been plauing the guitar for 4 years.
Объяснение: