... For, since, in and from: grammar exercise Complete the following sentences using for, in, from or since. 1. I once studied the piano ………………………… three years.a) since b) for c) in 2. That ... …………………… two years.a) since b) for c) from 3. I have known her ………………………. a long time.a) for b) since c) from 4. We go away ……………………. three weeks every summer.a) for b) since c) in 5. How long are ... ………………………?a) for b) in c) from 6. It was the worst storm ……………………. years.a) for b) in c) either could be used here7. I will be here …………………… four o’clock onwards.a) from b) since c) either...