试题题干
Fill in the blanks with an item as required.
With a relative pronoun or relative adverb：
The process by 
energy is changed from one form into another is called the transformation of energy.
参考答案
试题解析
本题考查限定性定语从句中的关系代词。
由先行词the process后面有介词by，可知用关系代词which，指代前面的process，by which就是by the process，通过这个过程。
句意：能量从一种形式变为另一种形式，这一过程称为能量转换。