单项选择题In America, high school graduates have to take ______ in order to enter prestigious universities.
单项选择题Canada comprises ______ provinces and three territories.
单项选择题The study of how we do things with words is the study of ______.
单项选择题Charlotte Bronte's masterpiece is ______.
单项选择题In communication one may shift from formal English to informal English or from standard English to non-standard English. This is known as ______.