单项选择题 The introduction of ( )had a great infuence on English vocabulary. The words such as 'abbot, 'amen' and 'apostle' are some of the example words.

单项选择题 By ___, words fall into functional words and content words.

单项选择题 Some morphemes are realized by more than one morph according to their position in a word. Some alternative morphs are known as___.