—You were brave enough to raise objection at the meeting. —Well, now I regret ________ that.
To reduce emissions of greenhouse gases, many countries are increasing the use of natural gas, wind and other forms of _______ energy.
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.