Замените времена группы Indefinite временами группы Continuous
дополнив предложения обстоятельствами времени: now, at 11 o’clock, when you came, from… to, all the day, где необходимо. 
1. First-year students work in the anatomy museum. 2. He will make ;i report on the muscular system. 3. She prepared the text «Voluntary and Involuntary Muscles» at home. 4. We translated 5 sentences from this text. 5. Last Monday we had a practical lesson on the structure and functions of smooth muscles.

First-year students are working in the anatomy museum now.

He will be making a report on the muscular system at 11 o’clock.

She was preparing the text «Voluntary and Involuntary Muscles» at home all the day.

 We were translating 5 sentences from this text when you came.

Last Monday we were having a practical lesson on the structure and functions of smooth muscles from 5 to 7.