С. : fill in a, an or the where necessary.1) the local community of collingwood in 2) … sydney is abuzz with news of 3) … unusual humming sound coming from 4) … preston park. 5) … sound was first noticed by 6) … group of children who were playing 7) … football at 8) … park. as one of 9) … children said: "it was 10) … strangest thing i've ever heard, it sounded like someone humming 11) … song really, really loudly." later in the same week, more visitors to 12) … park heard 13) … mysterious sound. eventually, the police was called upon to investigate 14) … matter. by now, the strange hum had become extremely loud and could be heard all over 15) … area. "sometimes it's worse at 16) … night, 'said mrs jacobs, 17) … local resident. later in 18) … … week, 19) … … team of scientists will come to collingwood in 20) … effort to solve 21) … mystery of the humming noise.​

1. He (studied) better than his father (had done). 2. They (spent) their vacation last year at the same village where they (had lived) many years before. 3. When we ( came) she had already ( sent) the children away and (was free) to speak to us. 4. Yesterday I (bought) a new watch as I (had lost) my old one. 5. He (took) the boy to the door by which he himself (had entered) the room. 6. He ( opened) his eyes, then ( looked) around and (thoght) for some time, trying to remember what (had happened) to him. 7. After they (had travelled) in the Caucasus they (decided) to make a sea voyage. 8. After they (had gone) at last I (went) to bed. 9. He (ate) all the cakes after we (had told) him not to do it. 10. The day after the party he ( asked) why we (had left) so early.

1. Nina celebrated her birthday yesterday. Her room looked beautiful, there were many flowers in it. When I came in, somebody was playing the piano, two or three pairs were dancing. 2. Listen! Somebody is playing the piano. 3. I  like music very much. 4. When I  looked out of the window, it was raining heavily and people were hurrying along the streets. 5. What  were you doing at seven o'clock yesterday? — I was having supper. 6. When I  came home yesterday, I  saw that all my family was sitting round the table. Father was reading a letter from my uncle who  lives in Paris. 7. Where were you  yesterday? — I was at home the whole day. — How strange. I rang you up at two o'clock, but nobody  answered. — Oh, I was in the garden. I was reading your book and did not hear the telephone. 8. What wereyou  doing at five o'clock yesterday? — I was working in the library. — I was there, too, but I did not  see you. 9. Yesterday I was working at my English from five till seven. 10. It was raining the whole day yesterday. 11. Where is your sister  now? — She is in her room. She is doing her homework.