若f（n）表示n²+1（n∈N^*）的各位数字之和，如：6²=36，36+1=37，3+7=10，则f（6）=10，记f₁（n）=f（n），f₂（n）=f（f₁（n）），…f_k+1（n）=f（f_k（n））（k∈N^*），则f₂₀₀₉（8）=______．

用所给单词的适当形式填空。

1. Must we _____( start) the work at once?

2. —Where _____ (be) our English teacher?

    —She _____ (talk) with some students over there.

3. Mary got a lot of presents on her _____ (twelve)birthday.

4. Beijing is a very nice place_____ (live) in.

5. What time _____ Mr Read _____ ( have) lunch every day?

6. I _____ (do) the washing tomorrow.

7. We _____ (not have) any classes next week.

8. They all like to _____ (call) me Bob.

9. They are beginning _____ (pick) the apples.

10. I want to go to the city _____ (call) Shanghai.