垫厚度将上下前牙离开多少最为适宜（）。
A.3mm
B.5mm
C.0.5～1mm
D.0.3～0.5mm
E.1.5～2mm
参考答案：D
— My parents died when I was very small, and I started to make a living by selling newspapers
at the age of ten.
— I really have much ________ for you. [ ]
A. belief
B. pride
C. sympathy
D. strength
分泌型IgA产生主要部位是()
A．脾
B．骨髓
C．黏膜相关淋巴组织
D．淋巴结
E．外周血
垫厚度将上下前牙离开多少最为适宜（）。
垫厚度将上下前牙离开多少最为适宜（）。