入睡最浅、最易唤醒的睡眠时期是（）

A.慢波睡眠的第I时相

B.慢波睡眠的第Ⅱ时相

C.慢波睡眠的第Ⅲ时相

D.慢波睡眠的第Ⅳ时相

E.快波睡眠

She managed to be back on her feet and,               , continued to look upon life as a positive experience.[ ]

A. to her surprise

B. to her credit

C. to her knowledge

D. to her face