Complete the following passage with the words or phrases in the box. Each word or phrase can only be used once（将下列单词或词组填入空格。每空格限填一词，每词或词组只能填一次）

A.directions       B. part        C.signs       D.easier        E.active

Every now and then, you may hear satellites sent into space.Why do we need so many satellites? What do they do for us?

At present, there are more than 3,000 【小题1】 satellites moving around the earth. Satellites have all kinds of roles, from transmitting TV signals giving you 【小题2】 on the road, to helping scientists with their research.

For example, the 22 satellites China sent up on February 27 are 【小题3】 of the BeiDou Navigation Satellite System. Shared bikes that use BeiDou chips can provide more accurate positioning. It will make them 【小题4】 to find Drowes (无人机)can also use BeiDou to fly.

A. predict       B.united          C.disasters       D.block        E.distances

Before we have satellites, TV signals didn’t reach very far. Mountains or tall buildings would 【小题5】 the signals. Phone calls to faraway places were also a problem. Setting up telephone wires over long 【小题6】 is difficult. With satellites, TV signals and phone calls can be sent directly to the satellite and back to different locations on Earth.

Satellites can also provide information about clouds,oceans,land and ice. They help scientists 【小题7】 changes in weather and climate. By monitoring wildfires and volcanoes(火山) satellites help deal with natural 【小题8】. Farmers can use satellite images to decide the best time to water their fields. Some satellites fly near other planets. They may look for water on Mars or take close-up pictures of Saturn's rings.