（Is ）your sister ( doing）her homework? （Has ）your sister ( d

问题描述：

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最佳答案：

1.（Is ）your sister ( doing）her homework? 

   （Has ）your sister ( done）her homework?

 （Did ）your sister ( do）her homework?

  （Will）your sister ( do）her homework?

2.Let's ( do) our homework now.