Ex.2
1. How long have you been doing your homework?
I've (have) been doing my homework since 5 o'clock.
2. How long has Grandma been using my laptop?
She's (has) been using my laptop since dinner.
3. How long has he been giving the lecture?
He's (has) been giving the lecture for 30 minutes.
4. How long have you been developing the products?
I've (have) been developing the products for three years.
5. How long have they been working as part of a team?
They've (have) been working as part of a team since last week.
6. How long have you been writing this program?
I've (have) been writing this program for two days.
7. How long has his little brother been using touchscreen?
He's (has) been using touchscreen since he was two years old.
8. How long have you been wondering how this gadget works?
I've (have) been wondering how this gadget works for three hours.
