麦角胺治疗偏头痛的可能机制是
A.阻断血管平滑肌上的α受体
B.直接扩张脑血管,改善脑组织供氧
C.收缩脑血管,减轻动脉搏动幅度
D.具有镇痛作用
E.中枢抑制作用
参考答案:C
The meat smells _______. Maybe it goes _______.
A.terribly; badly
B.terrible; bad
C.terrible; badly
D.terribly; bad
Washington, a state in the United States, was named _______ one of the greatest American presidents.
A.in honor of
B.in spite of
C.in favor of
D.in face of