On English countable nouns and uncountable nouns Examples and usage are attached, 1.The novel is one of his best _______ ,and it is _______ to understand it. A.work...a hard work B.works...a hard work. C.work...hard work D. works.hard work. Why? 8.The mother asked her son to help her because she had ____ in sending e-mails. A.some difficulties B.many difficulties C.a difficulty D.some difficulty D. Why? 9.Through the teacher made _______ to persuade her students to change their ideas when choosing majors in the university,media and social circumstances had __________ on their choices. A.effort...a great effort B. efforts.great effects C.an effort...great effect D.effort...great effects Why?

On English countable nouns and uncountable nouns Examples and usage are attached, 1.The novel is one of his best _______ ,and it is _______ to understand it. A.work...a hard work B.works...a hard work. C.work...hard work D. works.hard work. Why? 8.The mother asked her son to help her because she had ____ in sending e-mails. A.some difficulties B.many difficulties C.a difficulty D.some difficulty D. Why? 9.Through the teacher made _______ to persuade her students to change their ideas when choosing majors in the university,media and social circumstances had __________ on their choices. A.effort...a great effort B. efforts.great effects C.an effort...great effect D.effort...great effects Why?

1 work is not countable when it is said to be a work, but it is countable when it is translated into a work or a work
First of all, the phrase "have difficulty in doing" has difficulty in doing something
In fact, I think it's all right to use that form, but it's necessary to distinguish between them. The word "effort" is an uncountable noun when it refers to the energy and strength of doing something. Make the effort to do is translated into "make the effort to do", but it's also a countable noun when it refers to "make an effort to do", The second empty phrase "have an effect on" should also be put in the sentence, because the sentence means that the media and social environment have an impact on their choice, so it can be imagined that the impact is multifaceted and many, By the way, one out of four is called choose the best answer in English. Choose the best answer