【单选题】I know him ____ but I have never actually spoken to him.
【单选题】I knew her ______ but I have never actually spoken to her.
【单选题】焊接结构的疲劳强度的大小与( )关系不大。
【单选题】首先提出了“言”“意”“象”关系问题的中国古代文献是:
【简答题】489÷6商的最高位是______位,489÷3商是______.
【多选题】下列牌号的铸铁中,( )为灰铸铁。(基础知识)