A CharSequence provides only a single method for accessing its characters: charAt (x).

CharSequence只提供了一个方法来访问它的字符：charat (x)。

The reason is that Rope represents lazy substrings using a dedicated class, allowing the implementation of charAt to remain simple for regular ropes.

原因是 Rope使用专门的类来表示延迟子串（lazy substring），因此使普通 rope 的 charAt的实现保持简单。

To enable this new capability, the Rope's charAt method can be modified so that, on the first invocation, an iterator is constructed at the specified position.

为了支持这一新功能，可以修改 Rope的 charAt方法，这样在第一次调用的时候，就在指定位置上构建一个迭代器。

For the calibration in high temperature, the K which is re-lated to the reciprocal of sensitivity C of the sensor is adopted as charat-eristic factor, which brings convenience to users.

在高温标定时，采用与传感器灵敏度C 有倒数关系的K 值作为传感器的特征系数，给使用者带来方便。