nucleus nervi trochlearis

例句：

1. 1.The nucleus of the cell is where DNA is stored.
   细胞的核心是DNA的存储地。
2. 2. The heart's nucleus controls the rhythm of the heartbeat.
   心脏的核心控制着心跳的节奏。
3. 3. The nucleus of the planet is the sun.
   行星的核心是太阳。