如图，一艘海轮位于灯塔P的北偏东30°方向，距离灯塔60海里的A处，它沿正南方向航行一段时间后，到达位于灯塔P的南偏东45°方向上的B处，这时，海轮所在的B处与灯塔P的距离为（　　）

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You Can Make a Windsock(风筒)

    Have you ever seen a windsock blowing in the wind? Well, you can make one of your own! This is a fun project that you can do with things you may have. You just need to follow a few easy steps.

You will need:

●one piece of heavy colored paper   ●five ribbons

●strong tape       ●a string

●a pencil

What to do:

Step 1: Draw pictures on the paper. You can write your name on it. Do anything that will make it special to you.

    Step 2: Make the paper into the shape of a tube. Hold one of the shorter edges(边缘) over the other. Then make them together with the tape at each end and in the middle.

Step 3: Use a pencil to make a hole into both sides of the tube. The holes should be only on one end of the tube. Pull the string through both holes. Then tie the ends of the string together.

    Step 4: Now make five holes around the top of the other end of the tube.Put a ribbon through each of the holes. Tie a knot in the ends.

    Make sure the knots are bigger than the holes.

    Now your windsock is ready to use, but how does it work? The shape of the tube plays an important part. Wind blows through the tube and makes it fly and dance around. Hold the windsock up in the air by its string and run around. It will fly behind you. You can also hang it outside and watch it dance around on its own!