单项选择题He was a person who would stand up for what he thought right, ______.
单项选择题You can't be ______ careful in making the decision as it was such a critical case.
单项选择题Problems common to most countries include the social, economic ______ problems.
单项选择题These excursions will give you an even deeper ______ into our language and culture.
单项选择题He is ______ of a musician.