But if a treatment ________ delayed the disease by seven years were to be available, the number of sufferers would drop by 40% by the middle of the century.
—Did you know any French before you arrived in Washington? —Never ____ it, actually.
____ the search engine just gave me some brief introductions rather than the whole content of the book to read.
The program is like a window on the world ____ you sit by it and fix your attention on what it shows.
—Ms Lin looks rather a kind lady. —But in fact she is cold and hard on us. You ____ believe it!
Will you see to ____ that my birds are looked after well while I’m away?