下列说法中不符合"持续性心境障碍"的主要特点的是（）。

A.每次发作极少严重到足以描述为轻躁狂

B.情绪高涨与情绪低落交错发作

C.持续性并常有起伏的心境障碍

D.不足以达到轻度抑郁

Although some unexpected difficulties have ________ in the process, we are confident that we can handle them.

A．risen

B．raised

C．arisen

D．aroused