第1个回答 2012-07-21
hard 动词harden 名词是hardness
addition 动词add 形容词additional 副词additionally
weakness 动词weaken 形容词weak 副词weakly本回答被网友采纳
第2个回答 2012-07-21
harden hardness add additional additionally weaken weak weakly
第3个回答 2012-07-21
hardship
add additional
weaken