由题意可知,f(4)=f(2)=f(0)=0
故答案为:0
患者,男性,50岁。腹胀伴纳差、乏力2年。2小时前突然呕吐鲜血约800ml,查体:血压95/55mmHg,脉搏每分钟120次,巩膜黄染,肝脾肋下未及,移动性浊音(+),化验ALB27g/L,TB32.6μmol/L,HBsAg(+)。
为明确诊断,待出血稍稳定后应首选的检查是()
A.上消化道钡剂
B.CT检查
C.MRI检查
D.血管造影
E.纤维内镜
The other day, my father drove his car at _______ I thought was a dangerous speed.
A.why
B.what
C.how
D.that