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 ______.
单项选择题The author of Sister Carrie is ______.
单项选择题What impressed the author most when he went to watch the lions in the Gir Forest
单项选择题Why are the lions in the Git Forest especially vulnerable to disease