---- Dad , why should I stop ____ computer games ?

----- For your health , my boy , I’m afraid you _______ .

A．to play; must

B．playing; have to

C．to play ; can

D．playing ; may

乳腺癌的声像图特征是（）。

A.边界不整，呈锯齿状，无包膜

B.内部呈低回声区

C.后方回声呈衰减暗区

D.肿块向周围组织及皮肤浸润

E.以上都是