1.She has lived here for 10 years.
2.She has been living here for 10 years.

請問，這兩句意思是不是相同啊？

另外，我看到文法書講"過去完成式"，
請問，如果主詞是我的話，
是I "had" written a letter when she came.
還是I "have" written a letter when she came.

謝謝大家