Ответ:
1) She isn't reading the paper.
2) Jein is playing the piano.
3) Is Sandy playing tennis now?
4) Liz and Jane are cooking dinner now.
5) Where are you walking?
6) Where are they going?
7) We aren't drinking coffee, we are drinking tea.
8) Ben is standing by the window.
9) He is looking out at the garden.
10) What are you thinking?