1 how to communicate with
2 much too difficult / hard为什么要用how呢？？如果是learning to communicate with others in our daily life is very useful或者是learning communicating with others in our daily life is very useful 都是正确的表达，但你给了四个空，所以只能是 how to communicate with这四个词可是句子不是“在日常生活中怎样学会与人交流时很有用的”啊这三种表达法都是一个意思。