水力通沟是利用水力的原理进行通沟的。
正确
暂无解析
Theoldmanshouldbetreatedwith____.
Adultssometimesenvychildrenwhoplayallthetime____theythemselveshavetowork.rainorshine.
题目：抱怨和索赔信函
Asisknowntousall,theage_____childrencangotoschoolisseven.
Theforeigners_________there,butthey_________thefoodthereatfirst.
