effect，influence是不可数名词吗？

它们既可作可数名词又可作不可数，要看具体情况，请看字典解释：
effect
名词 n.

1.结果[C][U][(+on/upon)]
2.效果,效力;作用;影响[C][U][(+on/upon)]
This had a great effect upon the future of both mother and son.
这对母子俩的将来影响很大。
3.要旨,意义[the S]
I said a few words to the effect that all he had told us was already well known.
我说了几句话,大意是他所告诉我们的一切早已为人熟知。
4.(法律的)效力,产生效力[U]
5.(色彩,声音等产生的)印象;效果[C][P1]
6.财产,动产[P]

及物动词 vt.

1.造成;产生;招致
Rose tried to effect a reconciliation.
罗丝试图进行调解。
2.实现,达到(目的)
He effected several important changes.
他完成了几项重要的改革。

名词 n.

1.影响,作用[C][U][(+on/upon)]
The influence of climate on crops are self-evident.
气候对农作物的影响是不证自明的。
2.影响力;势力,权势[U][(+over/with)]
Mr. Smith is a man of influence in this town.
史密斯先生是这个镇上有权势的人物。
3.有影响的人(或事物);有权势者[C][(for/on)]

及物动词 vt.

1.影响,感化;左右[O2]
I don't want to influence you. You must decide f