fever on and off

例句：

1. 1. She has been feeling a bit under the weather lately, so she's been having these occasional fevers.
   她最近一直有点不舒服，所以偶尔会发些烧。
2. 2. During her recovery from an illness, she often experiences this kind of fever on and off.
   在她从疾病中恢复期间，她经常间歇性地发烧。
3. 3. Doctors are concerned about the possibility of a recurring fever for someone who has just recovered from a severe infection.
   医生们担心，刚刚从严重感染中恢复的人可能会再次出现间歇性发烧。