Use in, on, at, by, until if necessary.
1. Students usually have their exams___the end of each term. 2. The book was rather simple. I read it___ a day. 3. He switched on the radio and TV___the same time. 4. It was difficult to persuade her but___the end she agreed to our proposal. 5. He is very punctual, his lectures always begin___time. 6. She nearly forgot about their meeting, but fortunately she remembered it___ time. 7- They will be working ___ 7 o'clock today. 8. Hurry up! I'm afraid,___the time we get to the station, the train will have already left. 9. Have you finished translating the book? — Not yet. I hope to finish it___ the end of the month. 10.___what time did he come? — He came late___the evening,___midnight, if I am not mistaken. 11. Boogie-woogie became popular in the United States .___the 1950s. 12. They came back___sunset, tired and hungry. 13. They went to the canteen ___ lunchtime. 14.___the past he used to be a skilled surgeon. 15.1 am sure, he will be well again___several days.