it is difficult to understand scotish people if you () their

it is difficult to understand scotish people if you () their It is difficult for people to understand his action; you can This question is very difficult.( )people can understand it. 1.Lesson is very difficult,but _____ people understand it. it is difficult to understand.中的to是什么词 It is difficult to understand what she has said it is difficult to make myself(understand)in that place. It is difficult to get books back from people to whom you ha If I understand what is love ,it is you doing . he or she may find it difficult to understand what people th I said if you really understand what is it good you may find it difficult to understand them,为什么IT后面跟形容此呢?