answer:"back hurting"翻译成中文是"背部疼痛"。

answer:"back hurting"作为一个短语在日常口语中还可以表示心烦意乱、烦恼等负面情绪。例如：My boss has been really difficult to work with lately and it's really been hurting my back (我的老板最近很难相处，让我感到非常烦恼)。

answer:An array is a data structure that represents an index-based collection of a fixed number of homogeneous data elements. This means that all the elements in the array have the same data type, and the array starts from index 0. The size of an array in Java is fixed; once an array is created, its size cannot be changed. In Java, arrays can be of primitive data types or reference types. The main purpose of an array is to store multiple values in a single variable, instead of declaring separate variables for each value.

answer:An array is like a fancy organizer that holds a fixed number of things that are all the same type, starting from 0. Once you create it in Java, you can't change its size. It can organize either things that are the basic building blocks of data (like numbers and letters) or things that refer to other things (like objects). The point of using an array is to store lots of values in just one variable, instead of having to make multiple variables for each value.