这句话几个句子,几个主谓宾,分别是什么Wewish,however,tomakeitclearthatinourfuturetransactions,involvedforeachtransactionislessthanUS$5,000ortheequivalentinRenminbiShouldtheamountexceedthatfigure，paymentbyl

　　这句话几个句子,几个主谓宾,分别是什么

　　Wewish,however,tomakeitclearthatinourfuturetransactions,involvedforeachtransactionislessthanUS$5,000ortheequivalentinRenminbi

　　Shouldtheamountexceedthatfigure，paymentbyletterofcreditwillberequired.

　　没写完，补上后半部分

　　involved在这里做定语，形容词，还是谓语动词。exceed呢，should是怎么回事，