28. The book was written _____ careful observations and detailed studies.
If I ________ your advice then, I think that the crops could be growing better.
If you ________ home without a word, your parents wouldn't be so worried now.
We ________ here on time but we were caught in a traffic jam.
—Can you keep a secret?—You ________ worry—I'm not going to mention it to anyone.
For those of you who ________ a few very popular articles that came out last week, check out this mail.