题目

科学家发现，一种名为“绿叶海蜗牛”的动物在摄取藻类后，能够将藻类的某一细胞结构置于自己的细胞内，从而使自身也能进行光合作用。该细胞结构是() A . 液泡 B . 叶绿体 C . 细胞膜 D . 细胞壁 答案：B 　　Venice hoteliers(旅馆经营者)are urging tourists to enjoy the tourist mecca(圣地)despite constant flooding, offering free rubber boots for guests to wander around the Renaissance city． 　　“Venetian hoteliers and Mayor Massimo Cacciari reassure tourists who want to come in Venice：Don't worry, there is no danger：high water is a phenomenon that quickly disappears,” says an industry website, www.veneziasi.it．A special 190 euros(250 dollar)a night package includes “free use of rubber boots to walk during the high water,” along with a map showing where special platforms are erected along the canal city’s streets during the flooding． 　　Venice has been under water for nearly two weeks, reaching a 22-year high on December 1 at 1.56 meters(5 feet, 2 inches)．Thursday and Friday are expected to see highs of up to 1.30 meters．The lagoon city(水城)was flooded 50 times between 1993 and 2002, but by far the worst incident was on November 4, 1966, when it remained under water by 1.94 metres of water amid catastrophic flooding throughout Italy． 　　Every new flood brings disputes over a complicated project to place hinged panels(活动闸门)at the entrance leading into the lagoon．Mayor Cacciari is among critics of the so-called Moses Project, which was launched in 2003 and is not expected to reach completion until 2012．Under the scheme, 78 steel panels will lie on the seabed．When high tide is more than 1.1 metres above normal, compressed air will then force the panels to rise up on their hinges, forming a slanting(倾斜的)barrier to the incoming tide from the Adriatic Sea．Another approach under consideration is to raise the city's buildings．Under Operation”Rialto”, piston-supported poles(活塞柱)would be placed beneath each structure and gradually lift buildings by up to a metre． 　　Experts say the severity and frequency of floods is becoming worse due to silt deposits raising the floor of the lagoon and a rise in sea levels caused by global warming． 　　Bad weather has affected much of Italy in recent days, with snow storms in the north, heavy rain in Umbria and Tuscany and thunder storms over Rome and as far south as Sicily． (1) Why do Venice hotel owners offer free boots? [　　] A． To introduce the city’s one of the new tourist attractions． B． To promote their hotels service and booking rates． C． To make it a necessity for travelers to wander around the city． D． To help travelers out of danger in the heavy rain． (2) According to the passage, what’s the mayor’s attitude towards“Rialto”? [　　] A． Negative． B． Supportive． C． Neutral． D． Unknown． (3) From the fourth paragraph, we know that ________． [　　] A． steel panels are expected to keep still when the tide reaches less than 1.0 metre． B． shops and homes had to use piston-supported poles to empty the water． C． the government has to raise the city buildings by up to a metre． D． several approaches to the problem arouse different opinions． (4) It can be inferred from the passage that ________． [　　] A． high water is a phenomenon that quickly comes and slowly disappears． B． Venice has been“under water”for 2 weeks, ranking the 1st high．in history． C． the city has adopted many ways to defeat the quick rising of water． D． the severity and frequency of floods is the result of the global warming