Thoughtheteachermade_______topersuadeherstudentstochangetheirideaswhen

Though 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 effectB.efforts ; great effectsC.an effort ; great effectD.effort ; great effects

B解析effort和effect本身都是不可数名词，但在词组中我们多用作可数名词。make efforts to do sth或make an effort表示“努力做某事”，而have great effects on sb或have a great effect on sb表示“对某人产生巨大影响”。这句句子的意思是“尽管老师努力劝说她的学生在选择大学专业时改变主意，但舆论和社会状况对他们的选择产生巨大影响。”

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