无痛觉

例句：

1. 1. The patient had a painlessheadache after the operation.
   病人手术后没有感到头痛。
2. 2. She was painless during the operation.
   她在手术期间没有感到疼痛。
3. 3. The newdrug is painless and has no sideeffects.
   这种新药不会引起疼痛，也没有副作用。