十二指肠球部以下出血
A.腹痛、发热、黄疸B.水量便鲜血C.出血伴腹痛高热D.出血速度慢、便血为主E.出血速度快、呕血或便血
参考答案:C
There was a time_____we went to the country and stayed with the farmers there.
A.which
B.that
C.when
D.while
比较固定汇率制度与浮动汇率制度的优缺点。