3.
阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。
Swimming is a good way to exercise. Do you know open water swimming? It means swimming in the sea, a river or a lake. Open water swimming is (enjoy), but there is a lot more to think about. It's very important to know how (keep) safe(安全的) in the water.
Most swimming (pool) make sure that the water is comfortable enough for people to get into. However, in open water swimming, the water is often much (cold), even in summer. It's not as warm swimming in the pool. many people like to wear a wetsuit(潜水衣) to help keep them warm.
If you want (swim) in the open water, here are some rules for you to follow. First, choose safe place. You can ask the workers there and they can tell you the safest place. Next, never swim by (you). Always have an adult swimmer beside you. Third, don't swim too far and stay close the river bank or the beach if you are in the sea.
Remember all these rules and you can have a great time swimming in the open water.
