The painter is clever in his ______of brushes and colors.

应该填employment还是application？

【答】应该填employment，意思是“使用”。

employment：: the act of using something 使用某具体物质或材料。

• We object to the company's employment [=use, utilization] of pesticides.

application： the use of an idea, method, law, etc., in a particular situation or for a particular purpose 应用、运用某法律、方法、想法、技术等抽象东西。

• Strict application of the rules is necessary in this case.

• the application of new information

• learning about the creative application [=use] of new technology

你的句子中，brushes和colors属于具体的东西，所以应该用emlpoyment.