Public service ads, also PSAs, often _________ for free, _________ to educate people about health, safety or any other problem that affects public welfare.
The lawyer was expected to _____ some proposals after reading all those documents.
_____ his knowledge of the mountainous country, John Smith was appointed as our guide.
Political parties often differ in their views on various _____ concerning their own countries.
Evidence obtained from observation and experiment is often used to _____ a scientific theory.
Jack is good, kind, hard-working and intelligent. _____, I can't speak too highly of him.