—Jack called to say that he would not accept the job.

—I had talked him into taking it up many times.________ since he still refuses.

A．I'll come to his help

B．I can't help it

C．I'll talk it over with him

D．I'll phone him up

与正常肝实质回声强度比较，肝癌回声可分为（）

A.强回声型和低回声型

B.强回声型和等回声型

C.低回声型和等回声型

D.强回声型、等回声型和低回声型

E.强回声型、等回声型、低回声型和混合回声型