一、Some facts and skills are learned by---------activities.

一、Some facts and skills are learned by_________activities.A.takingB.taking advantage ofC.keeping up withD.giving rise toD 不明白是怎么回事,如果可以的话求这句翻译二、Other adverbs of frequent are continually.frequent不是形容词吗?它怎么能在介词of后使用?三、The area of that city is about________that of this one.A.chargedB.to be chargedC.being chargedD.to have charged我想知道charge在这里是什么意思?还有为什么选D?