Xi. translate the sentences: 1. it is 3 o'clock. 2. it was cold in the laboratory yesterday. 3. it is said that he is an experienced engineer. 4. it is difficult to explain this phenomenon. 5. it seems this substance has desirable properties. 6. it is a.s. popov who invented the radio. 7. it was stuffy in the room. 8. was it thursday yesterday?