" Where do you come in your family?" According to Frank Sulloway, a US sociologist, the order in which we came【C1】______this world—first-born, middle or last-born—can not only help shape our personality(性格), it could【C2】______the success of our relationships, too. Sulloway has【C3】______more than 6 000 people over the past 26 years【C4】______an attempt to prove this theory: "Children compete for a【C5】______in the family", he says, "and if one role has already been【C6】______, later-born children have to choose【C7】______what's left". Because first-borns begin life with exclusive parental attention, they are often more【C8】______to accepting their parents' values,【C9】______later-born children,【C10】______to compete for a place in the family, may grow into rebellious(叛逆的) 【C11】______ 【C12】______if birth order has such an important impact on our【C13】______, does it affect our interactions with other people? Can we, for example,【C14】______the suitability of our【C15】______by their birth order?【C16】______says Sulloway, "Birth order is an excellent way of【C17】______whether a relationship will survive. For example, a【C18】______between a typical first-born husband who's dominating and assertive(武断的), and a later-born wife who likes【C19】______looked after, is very likely to【C20】______out".