缺词填空。

     Most children today go to a school where each class has its o   1    room. It was d   2    many years

ago. Most children w    3    to a one-room schoolhouse. In a one-room schoolhouse all the children

learned in one room from the s    4    teacher. A fourth grader might have sat next to a n    5    grader.

Possibly you have seen a one-room schoolhouse

o    6    a television program.

    There w    7    a good reason for many of the one-room schoolhouse.They were often in the countryside, where there were o    8    ten to twenty children going to school. Then one room was big e    9    for

everyone! Today there are many m    10    children going to school. The one-room schoolhouse has just

about disappeared.

熊胆的解痉活性成分为（）

A.（牛磺）熊去氧胆酸

B.去氧胆酸

C.麝香酮

D.蟾蜍甾二烯和强心甾烯蟾毒类

E.雄甾烷类