How can you tell which direction? By day, look for the Sun. _____________________________________________. At night, use the Big Dipper to help you find the North Star. It would be better to bring a compass because its needle always points north.
How do you know how far you have gone? ____________________________. Each step is about two feet. You’d better wear a pedometer which is a tool that counts steps. If you know where you started, which direction you are heading, and how far you have gone, you can use a good map to figure out exactly where you are.
Today there is a new way for travelers to figure out where they are. It is the GPS. It has 24 satellites that orbit the earth and ________________________. Someday you may carry a small receiver as you hike and use GPS to find out if you are there yet!
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作者: susan.sui 时间: 2012-3-23 10:33
1.it is in the east of morning and west in afternoon.
2.you could count every step.
3.constantly broadcast the positions.
