swim------swimming,write-----written,swim------swimming,drop------dropped,为什么它们变形都要双写两个字母?

swim为什么变成swimming? I like swimming还是swim? swim和swimming的用法. She can __and__is her favourite sport.A.swim;swimB.swimming;swimmingC.swimming;swimD.swim;swimming swimming ＆ swim可以说 (swim team) (swimming team)为什么只能说（swimming club）不能说（swim club） swimming club 还是 swim club?swim有时也是名词啊 swim club swim与swimming 怎么样区别呢? Tom can( ) A swim B swimming C to swim We often go (swim) there是swim 还是swimming? 请问swim和swimming的区别, went swimming 为什么swim要加ing swimming lesson为什么swim要加ing like ()A.swim B.swimming(怎么做)? swim现在分词是什么swimming还是swum swim和swimming有什么不同. 用swimming lesson还是用swim lesson Do you swim还是 Do you swimming They (swim;are swimming)in the river