单选题 (It) was (so) a long journey (that) we felt very tired (when) we arrived.
【正确答案】 B
【答案解析】[解析] so应改为such。此题考查so和such的用法。so的用法为“so+adj.+a/an+单数名词”;而such用于“such+a/an+adj.+单数名词”结构,故此处应为such。