大学英语四级阅读选词填空模拟题及答案解析.docx

第一篇 Climate change has claimed its latest victim：Limacina helicina，a planktonic，predatory(捕食的)sea snail that’s a member of the taxonomic group more(36) known as sea butterflies．(The name is(37) from the wing-like lobes(叶瓣)the tiny creatures use to get around．)In a study(38) published in joumal Proceedings of the Royal Society B，a group of scientists from the National Oceanic and Atmospheric Administration (NOAA)and Oregon State University have found that the Pacific Ocean’s decreasing pH—its acidifying( 酸 化 )，in other words-is dissolving L．helicina’s thin shells． The researchers collected sea butterfly(39) from 13 sites along the Pacific coast(between Washington and southern California，going over each with a scanning electron microscope．More than half of the shells(53％)from onshore individuals(40) signs of “severe dissolution damage，”while 24％of(41) individuals suffered dissolution damage．The study’ s(42) investigator, Dr. Nina Bednarsek of NOAA，described the affected L．helicina shells as having a texture not unlike “cauliflower” or “sandpaper．” According to the paper，there was a “strong positive(43) ” between the proportion of sea butterflies with severe shell dissolution damage and“the percentage of undersaturated(未达到饱和的)water ”near the ocean’ s surface．The researchers conclude“shell dissolution owing to(human．caused ocean(44) has doubled in near shore habitats since pre．industrial conditions across this region and is on track to triple by 2050，”a truly(45) prediction．Moreover, the broader implications for ecosystem are unclear, as damaged shells make it harder for ．L helicina to fight infections，stay buoyant，and protect themselves from predators． showed recently protected commonly derived samples offshore principal noticed correlation encouraging seaward acidification grim pollution 词性归类 * * 答案解析 第二篇 The social network will let user“s mute”messages from other users on their timelines without the muted person ’ s knowledge ， thereby avoiding the(