单选题 What I did for Mother that day was small, but it helped deepen the special {{U}}bond{{/U}} between us.

【正确答案】 A

【答案解析】bond：契约，亲和力，联系；tie：领带，关系，捆绑；rivalry：竞争，对峙，唱反调；collaboration：合作，共同；barrier：障碍。