钳工常用的刀具材料有碳素工具钢、（）工具钢、（）钢和（）合金等。
参考答案：合金、高速、硬质
If I ______ you, I would wear a beautiful dress in that party. [ ]
A. am
B. was
C. are
D. were
企业工会维护职工合法权益的主要形式和手段有哪些？
