The dams① aimed at saving Venice from the waves have been backed greatly. After eight year

The dams① aimed at saving Venice from the waves have been backed greatly. After eight years of argument, it plans to build 79 gates across three channels connecting the lagoon around Venice with the Adriatic Sea. The gates would be open most of the time but would be closed if there is a danger to the city.
The project, though, has run into fears that it could worsen Venice’s problems. The city throws waste into the lagoon, and environmentalists fear the dams will cause this pollution to bee worse if there is no tide to wash it out regularly. But if there is a tide, the flow can wash away about 550 million cubic meters of the lagoon in a single day, which means that by leaving the dam open for only a few hours, the waste should be cleaned out.
Another piece of good news is that British scientists are confident that the dams will be able to face an expected rise in sea levels caused by global warming. The gates are designed to stand a 22-centimetre rise in sea levels, but many scientists expect a global rise in sea levels of 31cm by 2100.
However, Trevor Davies and Isabel Trigo from University of East Anglia believe the dams are unlikely to broken. Climate change will weaken the local storms in the Adriatic that are the main cause of flood risk. Floodwaters are also a seasonal danger in Venice, usually because of a bination of spring tides and strong winds.
Venice, which rests on wooden piles driven into boggy③ ground, has been sinking for centuries, worsening the encroachment by the sea.
Notes:
① dam  n. 大坝
② lagoon  n. 泻湖
③ boggy  adj. 泥泞的
④ encroachment  n. 蚕食
Choose the best answers according to the above:
1. Which of the following is the main idea of the text?
A. Venice will not disappear into the sea.
B. Dams are designed to protect Venice.
C. Venice are facing dangers from the tides.
D. Global warming makes Venice worse and worse.
2. If the project es into use, the waste in the lagoon     .
A. will be washed away by the tides               B. will be sent to the higher places
C. will be carried away by workers                D. will have to be reused by humans
3. According to the idea of Trevor Davies, the dams won’t be broken because     .
A. the dams are higher than the buildings in Venice
B. there will be no tides or floods in the future
C. the climate all over the world will soon be cold
D. the storms in the Adriatic will be weaker in the future
4. According to the text, we can infer that Venice     .
A. has been sinking for hundreds of years
B. may suffer from spring tides and strong winds
C. will be under the sea sooner or later
D. will be a city with dams around except 78 gatesCADB