I try to understand ------that prevents so many people from

I try to understand ------that prevents so many people from When I try to understand —— that prevents so many Americans I try to understand _____ that prevents Mary from attending when I try to understand___it is that prevents so many 1.When I try to find out ______that prevents so many people 1道高中英语单选.I just don`t understand _____ that prevents so many When I try to understand __________that prevents children fr I just don’t understand_______ that prevents so many America I just don't understand __that prevents so many Americans fr 谁能帮我解释下这个为什么选C阿I just don't understand (. )that prevents so i just don't understand___that prevents so many Amerians fro I try and try to understand