I often have conversation with John over _____ phone, but keep in touch with Tom by writing _____ letters.
________ I be free tomorrow, I would go with you.
If he ________ my advice, he wouldn't have lost his job.
This printer is of good quality.If it ________ break down within the first year,we would repair it at our expense.
Maybe if I ________ science,and not literature then,I would be able to give you more help.(2011·北京)
Sorry,I am too busy now.If I ________ time,I would certainly go for an outing with you.(2012·湖南)