Supply the correct present tense and explain your choice:
1. My cousins (to work) very hard: Thomas (to study) for an exam and 1 (to practise) the piano for her first concert. 2. "What your father (to read) when he ir holiday ?" "He (to read) detective stories, but now he (to read) a science-fiction book 3. The pupils (to understand) now the use of the two present tenses ? 4. As soon as Man (to find) Michael's address, she will write a long letter to him. 5. Everybody (to kno that the Danube (to flow) into the Black Sea. 6. You can't talk to Jimmy now, He jue (to see) some specialists at the moment. 7. Grandmother (to cook) in the kitchen now she always (to cook) in the afternoons. 8. Four times twenty (to equal) eighty. 9. Look out ! Something (to burn) over there ! 10. The teacher generally (to sing) in English, bu today she (to sing) in French. 11. That little boy who (to walk) past our gate (to live) nex door. 12. We (to spend) this week-end in the mountains. We (to go) to the mountains nearly every week. 13. You always (to forget) where your keys are! 14. My aunt (to wear) that large hat because the sun (to shine) brightly today. 15. Trains (to travel) from Jassy to Bucharest in about five hours. 16. On her way to work mother generally (to meet) many children who (to hurry) to school. 17. I (not to know) why now you just (to be) silly. 18. "I (to see) that you (to wear) your best clothes. You (to go) to a party?" "No, I (to go) to a wedding." "And who is the unhappy man who (to throw) away his freedom ? You must tell him I (to feel) sorry for him! " “He (to speak) to you now!" (Stannard Allen, Living English Structure) 19. "What music the girl (to sing) next?" "She (to sing) an old Scottish song, She (to sing) it very well." 20. Mother (to think) this meat has gone bad. 21. This rule (to apply) to any person who (to apply) for this job?