mononucleosis

例句：

1. 1.He caught the flu and developed a mild case of mononucleosis.
   他得了流感，并患上了轻微的单核细胞增多症。
2. 2.The doctor diagnosed her with mononucleosis after testing her blood.
   医生在她的血液检测后诊断她患有单核细胞增多症。
3. 3. Mononucleosis is often caused by an infection or viral illness.
   单核细胞增多症通常是由感染或病毒性疾病引起的。