He said ______ his English teacher last year.[ ]
A. thanks to
B. thanks for
C. thank
A
男,60岁,腹痛、腹胀、停止排气排便20小时,1年前行开腹胆囊切除术。能提示应立即手术的最主要的指标是
A.体温38.5℃
B.明显腹胀
C.频繁呕吐
D.金属性肠鸣音
E.血压下降
有毒有害物质可分为几大类?