My cousin went to Canada two yours ago. He ______ there for a few months and then went to America.

A．worked

B．would work

C．would be working

D．has been working

呼吸系统严重疾病病人麻醉方法选择

A．胸部或上腹部硬膜外阻滞不适于严重呼吸功能障碍病人

B．上胸段硬膜外阻滞适用于哮喘病人

C．一般不选择腰麻

D．气管内麻醉适用于已有低氧血症的病人

E．吸入性麻醉药选用氟烷、中浓度的安氟醚和异氟醚