Thomas and Chess identified nine dimensions of temperament: activity level, regularity, approach, adaptability, intensity, sensory threshold, mood, distractibility and persistence.

托马确定了气质九个维度：活动水平、规律性、趋性、适应性、强度、感觉阈值、情绪、注意力分散持久性。

Rothbart explored other temperamental dimensions such as soothability and fear, as well as redefining the dimension of 'approach' as a baby's positive excitement and rapid advance toward new situations.

巴特探索了其他情绪维度，如安抚性恐惧，并重新定义了“趋性”维度，即婴儿对新情况积极兴奋快速推进度。

In other words, how did phototropism come to be?

换句话说，光趋性是如何形成？

Phototropism is growing in response to light.

光趋性是指植物着光源方生长特性。

The two plant ones we'll talking about are phototropism and then photoperiodism.

我们要讨论两种植物行为是光趋性光周期性。

And so let's start with phototropism.

让我们从光趋性开始讲起。