•I have an elementary knowledge of physics.我懂一些基本的物理知识。

•They made some elementary mistakes.他们犯了一些很基础的错误。

•Millions of travellers fail to take even the most elementary of precautions.上百万的旅客甚至没有采取最基本的预防措施。

•This book contains a series of elementary exercises for learners.本书含有为学习者设计的一系列基础练习。