Fill in the blanks with the correct form of the ‘Auxiliary Verbs’ given in the brackets in the following sentences :  1. When I ……………………. entered the room, the teacher started teaching…………………(have) 2. It was a winter night. We … ………. sitting round the fire. 3. (be)……………… he know your address? (do) 4. He must …… … received my parcel by now.(have) 5. Man ……………………….. the only animal that can laugh. (be) 6. The Head-Master ………………….. very disappointed. (be) 7. I… ………….. my homework at seven o’clock this morning. (do) 8. As he…………………. not there, I spoke to his brother. (be) 9. You ……………………… guilty. (be) 10. Since we……………….. late, we were not admitted. (be)