point particle

例句：

1. 1. The pointof the experiment is to find out howeffective it is.
   实验的目的在于找出它的有效性。
2. 2. The particle's behavior was unexpected.
   该粒子的行为出乎意料。
3. 3. The particle'ssize is crucial for its properties.
   该粒子的大小对其性质至关重要。