关于皮脂腺囊肿哪项正确

A．简称皮样囊肿

B．是皮脂腺排出管阻塞所致

C．与表面皮肤紧密相连，呈分叶状

D．与深层组织相连，活动性大

E．易发生恶变

—Please clean up the classroom. It's really a_____.

—OK. I'll do it at once.[ ]

A. mess

B. dirt

C. matter

D. trouble