—Would you have come to his help, had you been free? —Yes. But I______ engaged. 

I ___ a Leaguage member for six years.

Without this year’s Nobel Prize in physics winner Charles Kao’s idea of fibrotic（光纤的）communications, the “modern” telephone and Internet _________impossible．

----- I called at your house at about 7 o’clock yesterday evening, but you weren’t in.----- I _____ a film in the cinema.

— Hello, Tom. This is Mary speaking.— What a coincidence! I __________ about you.