present perfect的音标：present perfect的英式发音音标为：['prezənt 'pə:fikt]present perfect的美式发音音标为：['prɛznt 'pɚfɪkt]...

Sum up the new vocabulary in this Unit, and Present Perfect Tense.明确本单元所学的词汇和语法,增强他们正确操作的能力....

n.现在完成时...