If you hear more than six short blasts and one long blast of

On the high seas，a fog signal consisting of one prolonged blast followed by four short blasts would indicate the presence of a ______.

A.vessel being towed

B.fishing vessel engaged in trawling

C.vessel at anchor warning you of her location

D.power-driven pilot vessel on station underway

If you do NOT understand the course or intention of an approaching vessel you should sound ___________.

A.one short blast

B.one prolonged blast

C.not less than five short blasts

D.not less than five prolonged blasts

Believe it or not，the day when you can go to the moon is coming soon．You can go into space (11) space shuttle．It (12) about three days for the shuttle to go from the earth to the moon． The shuttle flies a long way to a space station． You can stay there for a short rest and then it will (13) you to the moon．

Now you can jump out of the shuttle． But you mustn't take (14) your spacesuit，because it is very hot in the daytime and very cold at night on the moon． The moon is much smaller than the earth． Things are (15) 0n the moon than they are on the earth． You can jump high every time you take a step． You will find that it is never tiring to walk on the moon． You don't need to take an umbrella or a raincoat with you，(16) there is no rain on the moon You can hear (17) because there is no air on the moon． And there are no animals or(18) living things there．

The moon moves more slowly than the earth，so one day on the moon is as long as two weeks on the earth and one night is just as long as two weeks on the earth． What could you do in (19 )long days and nights and in a silent world?' Now scientists are trying to make the (20) 0f the moon． But our earth is really a far better place to live，as long as we take good care of it，

( )11．

A．on

B．in

C．by

D．with

Approaching a anchorage in fog, you hear one short, one prolonged, and one short blast in that sequence on a ship’s whistle. This indicates ______.

A.A vessel towed

B.A vessel not under command and unable to maneuver.

C.A vessel anchored giving warning of her position.

D.A vessel stopped dead in the water.

If you hear more than six short blasts and one long blast of the whistle supplemented by the same signal on the general alarm, you should ______.

A.start the fire pump

B.go to your man overboard station

C.go to your lifeboat station

D.stand by for collision

You are on international waters during a heavy rainstorm and hear a vessel sounding a fog signal of one prolonged blast followed by two short blasts． Which of the following could it be？Ⅰ．A vessel laying submarine cable making way．Ⅱ．A pilot vessel on station at anchor．

A.Ⅰ only

B.Ⅱ only

C.Either Ⅰ or Ⅱ

D.Neither Ⅰ nor Ⅱ