Выберите правильную форму глагола, беря во внимание сослагательное наклонение: 1. It is essential

Выберите правильную форму глагола, учитывая сослагательное наклонение: 1. It is essential that the international cooperation (will be, should be) as productive as possible. 2. We were told that we (took, should take) part in the discussion. 3. A hypersonic craft will require complicated measures lest it (shouldnt, should) burn. 4. If he were a poet he (wrote, would write) good poems. 5. If Peter (phoned, had phoned) her, Jane wouldn39;t have been so annoyed. 6. I wish I (know, knew) what the answer was.