动火工作票级别一般分为（）。
A.一级
B.二级
C.三级
D.四级
参考答案：B
Tom looked at Jenny, tears ____ his eyes, and shouted out the words _____ in his heart for years. [ ]
A. filling; having hidden
B. filled; hidden
C. filling; hidden
D. filled; hiding
品种特征特性应具有相对稳定的一致性
