Scientists say they have found a way to produce the human body’s own cancer-killing cells through gene treatment, ______ new hope to cancer sufferers.

 — What on earth happened to that woman selling newspapers? — I don’t know. She ____ around here for a long time.

—I'm sure Andrew will win the first prize in the final.—I think so.He ________ for it for months.

I_____ violin lessons every two weeks, but I think I ‘ll make it every week from next month.

—What do you think of the book?—Oh,great.It’s　　a second time.