我发现要了解他的演讲主旨是很困难的。 I find it difficult to understand the purport of his speech.
研讨会旨在改革旧的封闭式的评价制度，从而建立新的教育评价体系。 The purpose of this seminar is to reform the old closed system so as to establish the new system of educational assessment.
这一政策旨在维护和平。 The aim of the policy is the preservation of peace.