. Jim was so badly burnt that at first they began to _____ of his life.
With the word “ PM2.5” _________ appearing in media reports, people pay greater attention to it and seek health tips for smoggy days.
Hiking is _____ great fun. You will get close to ____ nature and take exercise at the same time.
I couldn't imagine ______difficult it was for these badly injured victims to make it to the hospital.
—Where did you get this book?—I picked it up from a second-hand bookshop if you ______know.
—What are you two whispering about over there?—Oh, ______. Just small talk.