Each satellite broadcasts（）traffic on a designated channel.

A . taking the place of the radio system B . introducing a new life-saving system C . saving the vessels in distress D . improving the communication on land

A . 正确 B . 错误

A . DR B . BDR C . ABR D . ASBR

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

A . The message can be directed to the desired location B . The message can follow the earth‟s curvature C . The quality of message can not be affected by climatic D . the range of the message extend and the quality of reception is improved

A . NAVTEX B . EGC C . HF-telex D . all of above

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

A . always move slowly B . are in one place only C . sometimes move and sometime don‟t D . synchronize with the movement of the earth

A . communications in the whole system will stop B . the global system will be damaged C . the back-up one will take its place D . the whole system will not work

A . the range of antenna can cover everywhere in the world B . we can know the ship’s exact position C . that the distress alert can be located as soon as possible D . antenna of permanent earth stations may be directed towards fixed points in the sky

A.Once activated，these EPIRBs continuously send up a signal for use in identifying the vessel and for determining the position of the beacon B.The coded signal identifies the nature of the distress situation C.The coded signal only identifies the vessel's name and port of registry D.If the GMDSS Radio Operator does not program the EPIRB，it will transmit default information such as the follow-on communications frequency and mode

随体(satellite)

大卫星DNA(macro-satellite DNA)

A．no other country can make one like it B．it is much cheaper to operate C．it is more sophisticated than Landsat 7 D．Terra will show energy gains

是 否

A．communication B．communications