问题
选择题
—_____ is he?
—_____ my brother. [ ]
A. What, He's
B. Who, His
C. Who, He's
答案
答案：C
搜题请搜索小程序“爱下问搜题”
—_____ is he?
—_____ my brother. [ ]
A. What, He's
B. Who, His
C. Who, He's
答案：C
缺失，
固定义齿，松动。其松动的主要原因为（）