Откройте скобки. используйте простые или настоящие совершенные времена.
1. he (to give) his first lecture in banking in 2002. he (to become) a brilliant lecturer since.
2. we first (to observe) this effect in 2008. we (to make) good progress in studying it since.
3. i (to come) to work at this university in 2006. i (to publish) eight papers since.
4. some years ago my friend (to read) a book on the history of economics. he (to be) interested in studying economics since.
Объяснение:
1. gave, have become
2. observed, have made
3. came, have published
4. read, have been