单项选择题
下面哪一条语句是用于导入nltk中的英文词性标注的模块?
A.from nltk.corpus import treebank
B.from nltk import pos_tag
C.from nltk.stem import PorterStemmer
D.from nltk import word_tokenize
下面哪一条语句是用于导入nltk中的英文词性标注的模块?
A.from nltk.corpus import treebank
B.from nltk import pos_tag
C.from nltk.stem import PorterStemmer
D.from nltk import word_tokenize