The little island of Symi had a big party not long ago. Everyone sang and danced in the streets. Bells rang. Flags waved.

　　What was it all about?

　　For the first time, this island of Greece had its own fresh water. Women could fill their pails with all the water they wanted!

　　Very little rain falls on Symi. The people have always saved every drop they could get. But it has never been enough for their needs. They have had to buy water brought by ships.

　　Now Symi has its own “water factory. ” The factory changes salt water from the sea into fresh water that people can drink.

　　Most of the ways to turn salt water into fresh cost a lot of money. The Symi factory uses a way that costs very little.

　　What is the factory like? How does it work?

　　Right in the middle of the town are some long ponds (池塘).

　　Over each pond is a low tent. It is made of plastic that you can see through.

　　At night, sea water is pumped (抽) into the ponds. The next day, the hot sun shines through the tents. The sun's heat turns the water into vapor that rises from the ponds. The salt is left behind.

　　As it rises, the vapor becomes mist (轻雾). On the inside of each tent, the tiny drops of mist run together to make big drops. These run down the sides of the tent, filling a tank (桶) with fresh water.

　　The salt left behind in the ponds is washed out each night.Then more sea water is pumped in, The factory is, ready for the next day's work.

　　The tents and other parts of the factory cost very little. Sea water and sun cost nothing. Most people on Symi are poor. So to them this new way of getting fresh water seems wonderful!

1．The people on that Greek island held the big party because of ________ .

[　　]

A．their National Day

B．the harvest of the year

C．having fresh water of their own

D．drinking fresh water for the first time

2．From the story, we know that there might be a time for the people on the island ________ .

[　　]

A．to drink no fresh water at all

B．not to get enough fresh water as they wanted

C．to drink salt sea water most of the time

D．not to get any kind of water all their lives

3．Which of the following sentences is NOT true?

[　　]

A．The people on the island had been saving rain water.

B．The people on the island had bought water for drinking.

C．The people on the island have found many ways to make fresh water.

D．The people on the island have had a “water factory” of their own.

4．Water vapour is made in the factory by ________ .

[　　]

A．heating sea water by the sun

B．boiling sea water in the ponds

C．pumping sea water out of the ponds

D．filling the ponds with fresh water

5．________ in the ponds is washed out during the night.

[　　]