Раскройте скобки.употребляя глаголы в present perfect past simple past continuous или past perfect 1) columbus (not to know) that he (to discover) america 2)i already (to read) five english books. 3)he (to discuss) the problem with a lot of people before he (to take) a decision.
2)i have already read five english books.
3)he had discussed the problem with a lot of people before he took a decision.