义素
参考答案：
义素是理论分析的结果，是一种不与语音形式相联系的抽象的语义单位。
Tom ______ come with us together, but he is not very sure yet. [ ]
A. must
B. may
C. can
D. should
按功能性来划分，农业财政资金有哪些类别？
