exercise用法辨析

　　精神病患者不能行使选举权利的，经选举委员会确认，不行使选举权利。

　　例7：

　　The donor shall exercise his revocation right within one year after he knew or ought to have known the cause for revocation.

　　赠与人的撤销权，自知道或者应当知道撤销原因之日起一年内行使。