Rewrite the following sentences, using the words given.
4. My sister began to study English a year ago.
-> She has .....................................................................................................
6. Scientists began to fight against AIDS in 1980.
-> Scientists have ..........................................................................................
7. This hospital began to use laser treatment 5 years ago.
-> This hospital has been .............................................................................
8. She started working as a book keeper for this company 5 years ago.
-> She has .....................................................................................................
10. How long have you studied English?
-> When .........................................................................................................
11. The Browns have been living in London for 20 years.
-> The Browns began ....................................................................................
16. When did she begin to do research on lung cancer?
-> How long ...................................................................................................
4. My sister began to study English a year ago.
-> She has studied English for a year.
6. Scientists began to fight against AIDS in 1980.
-> Scientists have fought against AIDS since 1980.
7. This hospital began to use laser treatment 5 years ago.
-> This hospital has been using laser treatment for 5 years.
8. She started working as a book keeper for this company 5 years ago.
-> She has been working as a book keeper for this company for 5 years.
10. How long have you studied English?
-> When did you start studying English?
11. The Browns have been living in London for 20 years.
-> The Browns began living in London 20 years ago.
16. When did she begin to do research on lung cancer?
-> How long has she done research on lung cancer?