动物特征描述 — 英语填空题

看提示，根据句子意思从词库中选词填空，每词限用一次。词库：big, small, long, fast 1. The dolphin is not slow (慢的). It swims very ___. 2. The whale is not short (短的). Its body is very ___. 3. The shark is not small. It is very ___. 4. The sea horse is not big. It is very ___.