根据短文内容，判断下列各句正误。
Hong Kong has about forty public beaches. Some of them are very famous around the world. People can go there for a swim. You can go to them by bus. To go to some beaches you must take a boat.
You will swim there without danger if you remember these instructions:
Never swim alone.
Never go out in a boat if you cannot swim.
Never swim after a meal or when you feel hungry or tired.
Don't stay in the water too long.
Remember: A red flag means that it is dangerous for anybody to go into the water. A blue flag means that it is dangerous for children.
