Today, we’ll learn about four kinds of satellite (人造卫星).

The first kind of satellite studies the_________ of the Earth. People use it to help make maps. It also helps countries see where they may_________ oil or gold (石油或黄金).

People use the second kind of satellite to show_________ to ships and planes. A ship or a plane can send a message to the satellite. Then it can_________ where the ship or the plane is

The third kind studies the _________. People use these satellites to_________ clouds and strong winds moving across the Earth. They help countries make preparations (准备工作) when very _________ weather is coming.

What about the _________ kind of satellite? People use it for communication (通讯). These satellites can send telephone calls between _________. People from one country send the call to the satellite, and then the __________ sends it to a station in another country. Some can carry hundreds of calls at the same time. Also these satellites can carry pictures.