Anna has been ill in hospital for three weeks.（用since改写句子）

Anna has been ill in hospital for three weeks.（用since改写句子）
Anna has been ill in hospital for three weeks.（用since改写句子）

Anna has been ill in hospital for three weeks.（用since改写句子）
Anna has been ill in hospital since three weeks ago.

Anna has been ill in hospital since three weeks ago
It is three weeks since Anna got ill in hospital

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