食物嵌塞（）。
A．卡环臂未进入倒凹区
B．基托与黏膜不密合
C．卡环过紧
D．支托凹过深
E．有早接触
参考答案：B
5码＝______英尺
Such good use has been____ his spare time_____ his English has improved a lot.
A．made in; that
B．made of; which
C．made of; that
D．made out; as
支托凹过深
支托凹过深