--___________has he been like this?

--Ever since last week.

A．How long

B．How soon

C．How often

D．How much

X线片上判断有无牙槽骨吸收的标准是（）。

A.牙槽嵴顶与釉牙骨质界平齐

B.牙槽嵴顶到釉牙骨质界的距离>2mm

C.牙槽嵴顶到釉牙骨质界的距离>3mm

D.牙槽嵴顶到釉牙骨质界的距离<2mm