The best way to explore _______ countryside is on _______foot.
In most cases, college graduates don't mind what job they will do so long as it is one ______ they can earn money to support themselves.
__________ our efforts to save houses dating back to the Ming Dynasty, the local government decided to pull them down to build modern buildings there.
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.