比较级与最高级运用 — 英语词汇题
题目
At a school walking-club event, Route B is (long) ______ than Route A, but Route D is the (challenging) ______ of the four routes. Route C is (safe) ______ than Route D for beginners, while Route A is the (short) ______ route. Write the correct forms of the adjectives in order.