en结尾的动词？

widen(变宽)

broaden (变宽/阔)

fasten (使牢固)

frighten (使害怕)

strengthen (加强)

whiten(变白)

en结尾的v：strenghten,widen,brighten,broaden,weaken,sharpen,melten,shorten,lengthen,lighten,fatten

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