If you try to understand _____ that prevents so many Americans from being as happy as one might expect,

it seems that there are two causes. [ ]

A. what it does

B. why it is

C. why it does

D. what it is

患者饱餐后上腹部持续疼痛1天。查体：上腹部压痛、反跳痛。应首先考虑的是

A．急性胃炎
B．急性胰腺炎
C．急性肝炎
D．右肾结石
E．肝癌