研磨时研具的材料与工件的材料相比（），这样可使研磨剂的微小磨料嵌在研具上形成无数刀刃 发布时间：2019-01-22 01:21 │ 来源：www.tikuol.com 题型：单项选择题 问题： 研磨时研具的材料与工件的材料相比（），这样可使研磨剂的微小磨料嵌在研具上形成无数刀刃A.硬度低B.硬度相等C.硬度高D.可不作要求
题型：单项选择题 判断下列句子的表述是(√)否(×)正确。( ) 1. This is markers. ( ) 2. This is a chalk. ( ) 3. These are pencils. ( ) 4. These are my pen. ( ) 5. Where are Wang Lin? ( ) 6. How many books are there? ( ) 7. Her is reading a book. ( ) 8. Where is the chalk? 查看答案