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

Изберите 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 wouldn't have been so annoyed.
6. I wish I (know, knew) what the answer was.