被用作… is not required to 不一定 is referred to as… 被称为… is said to… 被认为… isolation [?a?s??le??n] n.隔离 it is good practice to …是一个好习惯 italic [??t?l?k] n.斜体 简写 i item [?a?t?m] n.项 interact with… 与…的交互 iterate [??t?re?t] v.迭代...