我的老师对植物学非常了解，能详细解释每种植物的特性。

My teacher is very ___knowledgeable about botany and can explain the details of each plant.

她是一位知识渊博的历史教授，对中世纪欧洲特别有研究。

She is a ___knowledgeable history professor, especially about medieval Europe.

她对计算机硬件非常了解。

She is very ___knowledgeable about computer hardware.