tend /vi:易于,倾向于,往往;泛指有做某事的倾向,或趋向于某种状况的倾向.
She tends to get angry if you annoy her.如果你使她烦恼,她容易(往往)发火
She tends to be sentimental.她往往多愁善感
(to sth)Idleness tends to poverty.游手好闲往往致穷
trend /n 趋势,潮流.意示一个总的变化发展方向,既无确定的进程,也无选定目标,它受某种外力影响而变化或变动.
Young women are always interested in the trend of fashion.年轻妇女总是对时装发展的趋势感兴趣
There is a trend towards simpler styles in women's dress.女装款式有向简朴发展的趋势
This indicates the general historical trend and this is what the people aspire,which nobody can defy.这是历史的大势所趋,这是人心之所趋,无人可以逆转.
这样讲述之后,你应该明白了吧?!
参考资料：汉英双解英语同义词词典