1. I have been thinking about it for 3 days already. – Pr. Perf. Cont.
2. а) My sister is drinking coffee with milk - Pr. Cont. если имеется в виду действие, кот. происходит в момент речи или
b) My sister drinks coffee with milk - Pr. Ind. - если просто говорится о ее предпочтении всегдаБ как в предложении № 3
3. I always prefer black coffee. - Pr.Ind.
4. Have you been still reading this book? - Pr. Perf. Cont.
5. How long have you been reading it? - Pr. Perf. Cont
6. My sister studies music. – Pr. Ind.
7. I have been looking for you the whole evening, where have you been?- Pr. Perf. Cont., Pr. Perf.
8. They have been writing a composition for 3 hours already. - Pr. Perf. Cont.
9. My friend has known English since his childhood. – Pr.Perf.
10. My mother is an actress. – Pr.Ind.
11. Look, somebody has broken a window. – Pr.Perf.