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單項(xiàng)選擇題

The satellites over the major ocean regions cover the globe（）.

A.besides the polar regions
B.including the North Pole and the South Pole
C.above 70N and below 70S
D.as far north and south 70

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單項(xiàng)選擇題

（）is a space system using one or more artificial earth satellites.

A.satellite network
B.Satellite Link
C.INMARSAT
D.Satellite System

單項(xiàng)選擇題

The establishment of INMARSAT as an independent organization marked a great step forward for maritime radio communications. What does “marked a great step” mean in the sentence?（）

A.To run faster than ever
B.To go forward
C.To march without stopping
D.A significant symbol of a great improvement in maritime communication