Подчеркните в каждом из них модальный глагол или его эквивалент и определите единрвременную форму. 1. Energy can exist

1. Energy can exist in many forms. (can) Present Simple 2. The chemists may use the reactor to analyse various substances. (may) Present simple 3. The engineer will have to explain this difficulty.(have to) Future Simple 4. You should follow all the important scientific researches in your field.(should) 5. He had to investigate a series of accidents. ( have to) Past Simple