stady、stop、leave、help、say、see、call、pick、buy的现在分词和过去式、过去分词

问题描述:

stady、stop、leave、help、say、see、call、pick、buy的现在分词和过去式、过去分词

应该是study吧?study-studying-studied-studiedstop-stopping-stopped-stoppedleave-leaving-left-lefthelp-helping-helped-helpedsay-saying-said-saidsee-seeing-saw-seencall-calling-called-calledpick-picking-...