I. замените подчеркнутые модальные глаголы соответствующими эквивалентами и переведите предложения на язык: 1. your friend can not do the laboratory work in time. you must help him. 2. nobody could understand this mysterious phenomenon. 3. the assistant may complete all necessary measurements himself. 4. you mustn't leave the laboratory if your experiment isn't finished. 5. she might use different methods in her research work.