骨骼肌细胞受刺激后，静息电位由-70mV变为-100mV时称为（）
A.超射
B.超极化
C.复极化
D.反极化
E.去极化
参考答案：B
Beijing ______ some strong winds, with dust blowing at 20 meters per second in the capital these days.
A．sees
B．saw
C．is seeing
D．was seeing
David felt ________of the foolish thing he had done in the classroom.
A．shameful
B．ashamed
C．shamed
D．shaming
