大学英语六级改革适用（阅读）模拟试卷776
词汇理解
If you\’re in the sea and walking through masses of plants in shallow waters with ticklish ribbons of green leaves, it\’s probably a seagrass meadow. They may seem a nuisance, but these modest plants are hugely important for the【C1】________of the oceans and atmosphere.
Seagrasses absorb and store vast amounts of carbon, and that helps to reduce climate change. Seagrass meadows have been calculated to store some 10 percent of carbon in the oceans, and per hectare they【C2】________ twice as much carbon dioxide as rainforests. They also lock away that carbon【C3】________as their remains pile up on the seafloor in carbon-rich soil up to several metres thick, if they are left undisturbed.
Seagrass meadows are widespread across many parts of the world, but in recent decades about a quarter of coverage has been【C4】________. Because they grow in shallow waters they are exposed to human 【C5】________from pollution and fertilisers running into the sea, anchors from boats and much else.
Restoring seagrass meadows would make it possible to increase greatly the carbon storage potential of the oceans and help【C6】________some of the excess carbon dioxide in the atmosphere. Restoration work is under way in the UK and many other places in the world, and is helped by the fact that seagrasses are flowering plants and very different from seaweeds. They have roots, stems, leaves, flowers and seeds, just like plants on land, so the work simply involves sowing the seeds, or planting small seedlings, on the seabed.
Seagrasses also have other huge benefits. They improve coastal water quality by absorbing nutrients and【C7】________fine sediments (泥沙), and provide important【C8】________for commercially important juvenile fish and crabs. The long blades of seagrasses also slow the movement of water, which【C9】________wave energy, giving some protection against coastal【C10】________and storm surges. And because seagrasses are underwater plants, they enrich the water with oxygen.
A) erosion I) perpetually
B) escapes J) reduces
C) health K) releases
D) hold L) spreading
E) interference M) temporarily
F) lost N) track
G) nurseries O) trapping
H) offset
1.【C1】
C
解析：空格前为定冠词the，后为介词of，空格词应为名词。空格句欲扬先抑，先让步指出海草床看似招人讨厌，后转折指出其实不然，海草对海洋和大气的________至关重要。联系空格后句(第二段首句)“海草床能吸存大量碳，有助于减缓气候变化”可知，空格句应体现“海草对海洋与大气的环境、状况、健康等至关重要”之意，备选项中C最合文意。
2.【C2】
D
解析：空格位于分句“…they(主)+________(谓)+twice…carbon dioxide(宾)”中，空格词应为动词。空格前句指出海草床的碳汇能力强，空格句进而以数据“海草床的碳储量约占海洋碳储量的10％(store…)，每公顷海草床________的CO2量是热带雨林的两倍”予以说明。由句间“解释说明关联”及句内“并列语义关联”可推断，空格词应与store同义，表“存储，吸纳”之意，D符合要求。
3.【C3】
I
解析：空格句内空格前主谓宾成分已完整(They“主”+lock away“谓”+that carbon“宾”)，空格后为as引导的原因状语从句，空格词可能为副词(修饰主句谓语或者整个as从句)、-ed分词、-ing分词或形容词(说明主句宾语that carbon)。空格句主句指出，海草床还可以________封存这些碳，从句as…if…交代主句情形发生的两个条件(表原因的as在某种程度上也指向了条件)：一、凋亡后的海草床堆积在海底厚达好几米的富碳土壤之中，二、海草床不受外界打扰。据此可推断句意逻辑：若不受外界侵扰，吸收大量碳的海草床在凋零衰落之后会携碳永久封存在海底深处，故空格词应表达“无限期地。长久地”等意，I正确。
4.【C4】
F
解析：空格位于分句“about a quarter…(主)+has been________”中，空格词词性分两种情况：当has been为系动词完成式时，空格词应为名词或形容词(作表语)；当has been________为谓语时，空格词应为-ed分词或-ing分词(分别构成现在完成时被动态、现在完成进行时)。空格句先让步介绍海草床分布地域广的特点，后转折指出全球海草床覆盖面积有大约1／4已经(是)________，可知空格词应传递
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