A portable dry chemical fire extinguisher discharges by ______.A.gravity when the extingui

A.Dry chemical and carbon dioxide

B.Foam (stored pressure) and soda-acid

C.Carbon dioxide and foam (stored pressure)

D.Dry chemical and soda-acid

A.Carbon dioxide

B.Water (stored pressure)

C.Dry chemical

D.Foam

A.foam and water

B.CO2 and dry chemical

C.dry chemical and water

D.foam and CO2

A.Test the pressure gauge for correct reading

B.Weigh the cartridge

C.Replace the dry chemical

D.Pressure test the discharge hose

The passage tells us that proof of life on Mars would______.

A．make clear the complex chemistry in the development of life

B．confirm the suggestion that bacterial fossils travelled to Earth on a meteorite

C．reveal the kind of conditions under which life originates

D．provide an explanation why life is common in the universe

According to Professor Morgan, what enables animals to freeze themselves？

A．A certain chemical in their bodies.

B．The change of certain circumstances around them.

C．A certain temperature.

D．A certain season in the year.

What is the main idea of the passage？

A．Reactions to the electric stress lead to more chemical yields.

B．Yields of commercially useful biologicals are increased.

C．Using electricity to elicit chemical production is very exciting.

D．Using electricity has a negative effect on plant growth.

The passage tells us that proof of life on Mars would______.

A．make clear the complex chemistry in the development of life

B．confirm the suggestion that bacterial fossils traveled to Earth on a meteorite

C．reveal the kind of conditions under which life originates

D．provide an explanation why life is common in the universe

材料：

Pride of Le Havre is a 33，336 gross tonnage passenger/ro-ro cargo vessel operating a regular ferry service between Portsmouth and Le Havre．The vessel is fitted with bow and stern doors and is capable of carrying 590 cars and 1600 passengers．Propulsion is by four diesel engines driving through two controllable pitch propellers．Two transverse thrust units are fitted forward.

The vessel had sailed from A&P&39;s King George V dry dock，Southampton，just after midnight on Thursday 18 March，for engine trials．The intention was that after these trials，Pride of Le Havre would berth at Portsmouth，and re-enter service later that day．

Shortly after passing the Nab Tower，the bridge fire alarm activated at 0425，indicating a fire in the machinery spaces．At about the same time，a motorman reported to the engineer watchkeeper that a fire had broken out on the starboard thermal oil pump．While initial attempts were being made to put the fire out using portable extinguishers，the chief engineer was called and the bridge informed of the situation．On confirming that the initial attempt had failed，the chief engineer advised the bridge that he proposed to use the Halon total flooding extinguishing system．The general alarm was sounded and the main engines stopped. The engine room was evacuated and sealed，with Halon being released at 0437．The coastguard and owners were told of the situation with a message being broadcast to local shipping．

A fire brigade team boarded at 0641 with re-entry to machinery space at 0958．Funnel vents were re-opened at 1030 with a fire extinguishing foam blanket laid down in the main machinery space．Ventilation of the engine room started at 1210 with full electrical power available by 1330．Under the direction of the chief engineer，the engine room crew started systematically checking and preparing machinery until，at 1750，No 4 main engine was started followed shortly afterwards by No 1 main engine．

Pride of Le Havre sailed under her own power back to Southampton where she re-entered the dry dock berth to undergo examination and repair．She was all fast alongside at 0033 on Friday 19 March 1999．

问题：

Pride of Le Havre is equipped with ________．

A.4 transverse thrust units，2 propellers，2 engines and 2 vehicle doors

B.2 transverse thrust units，2 propellers，2 engines and 1 vehicle door

C.2 transverse thrust units，1 propeller，2 engines and 2 vehicle doors

D.2 transverse thrust units，2 propellers，4 engines and 2 vehicle doors

The fire was put out by ________．A.a fire brigade team

B.the coastguard

C.owners

D.the crew

Should she have not been on fire，Pride of Le Havre would have re-entered the service on ________．A.Friday

B.Thursday

C.19 March

D.any day after 18 March

The using of the Halon total flooding extinguishing system was initially suggested by ________．A.the engineer watchkeeper

B.a motorman

C.the coastguard and owners

D.the chief engineer

请帮忙给出每个问题的正确答案和分析，谢谢！

A.excrete

B.scale

C.slow

D.portable