题干

How was Alice´s summer holiday?____
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答案(点此获取答案解析)

It was wonderful.

同类题1

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海洋垃圾能否变废为宝

      在人们的观念中,海洋有着世界上最博大的“胸怀”,对人类丢给它的那点物品完全可以“笑纳”,于是海洋被当成了天然的大垃圾场。时间证明人类会因为这个错误的观念和行为而付出巨大的代价。随着海洋垃圾的与日俱增,海洋生态景观受到破坏,对航行安全、海上作业、海上搜救也造成了极大的干扰。

                                                                                           垃圾岛成“新大陆”

      海洋垃圾是一个复杂的文化和跨部门问题,它对全球海洋、沿海环境和人类活动都具有重大影响。据美国科学组织统计,每年约有640万吨的垃圾进入海洋,平均每天约800万件垃圾入海,其中15%的垃圾停留在海滩上,15%的垃圾漂浮在水面上,超过70%的垃圾直接沉降进入海底。据估计,每平方千米的海域内,海洋垃圾的密度约为1.3万到1.8万个。

      在大西洋也发现巨型漂浮垃圾带,其规模比太平洋垃圾岛稍小。这一垃圾带距离北美海岸有数百英里,由数万块塑料构成。尽管目前科学家还未能准确测出它的宽度,但这一巨大的垃圾带覆盖的区域一直从北纬22度到北纬38度,几乎同古巴至美国弗吉尼亚州之间的距离相当。

                                                                                            危害人类健康

      有统计表明,世界每平方海里海水中有多达4万片的塑料垃圾。这些废弃塑料、渔网会缠住船只的螺旋桨,引起事故和停驶。塑料垃圾还会缠住海洋生物,使它们不能脱身,被饿死、窒息死亡或被其他动物吃掉。海洋垃圾是杀害海洋生物的元凶,例如海龟常常误食塑料袋,导致肠胃堵塞而无法进食,被活活的饿死;科学家曾解剖一只搁浅的小须鲸,在其胃中居然发现800千克的塑料袋。

      人类也不可避免地要受到海洋垃圾的威胁。有研究指出,塑料分解后的颗粒可以吸附海水中的有毒化学物质,这些毒素可以沿着食物链进入人类体内。一些垃圾会溶出有毒物质,直接威胁水体和沉积物环境质量,例如,纽扣电池进入海洋后,溶出的锰、汞、锌、铬等重金属将会污染水体,鱼类或贝类可能积累重金属并通过食物链传递给人类,如果长期积蓄将会损害神经系统、造血功能,甚至可以致癌。另外,由于一些微生物等物种“喜欢”附着在垃圾上,随洋流漂泊,可能会来到一个以前没有这种生物的地区,干扰这一地区的海洋生态系统。

                                                                                           可焚烧发电、制造燃油

      对将海洋垃圾变废为宝,科学家已开始了一些研究。一种办法是将海洋垃圾打捞后焚烧发电。由于几乎所有塑料都由不可再生的石油制成,主要成分是碳氢化合物,所以可以用于燃烧。其焚烧后的灰烬,则可以用于填海造地或建造岛屿。不过,焚烧海洋垃圾首先要解决搁置脱水的问题,而且由于塑料焚烧可产生大量的有害气体,会危及环境和生态,因此需要先解决控制有害气体排放的问题。

      另一种办法是用海洋垃圾制造燃油。由于海洋垃圾80%以上是塑料,可以用废塑料制造燃油、生产防水抗冻胶、制备多功能树脂胶等。目前,用废塑料制造燃油技术在一些国家已获得突破。

      如果这些技术成熟和投产,将可以大量地消化海洋垃圾,而且可能会让一些国家争抢这些海上无主的垃圾资源。

                                                                                                                                                                              (作者:蔡文清)

同类题3

阅读理解

    Love to sink into your chairs and relax when you get to school? Then you will not be happy to hear that schools all over the world are seriously considering exchanging traditional desks for ones with no seats at all — Yes, that means you will be encouraged to stand through those already too long math and science lessons! Why would anyone even think of putting kids to such cruelty? Experts say it improves their health and helps fight obesity. While that may seem a little far-fetched (牵强的), the officials at the few schools around the world seem to agree.

    Among them are educators from the College Station Independent School District in Texas, who recently completed aweek-long experiment involving 480 students across three elementary schools. The 374 kids that agreed to participate in the study were provided with adevice that helped record step count and calorie consumption over the entireperiod.

    All 25 teachers involved in the study reported that students appeared to be more alert and concentrate better, when allowed to stand. The one thing that did surprise the researchers was that younger kids were more willing to stay standing than kids in higher grades. They believe this may have something to do with the fact that after years ofbeing asked to “sit still”, older kids have a harder time adjusting to this unexpected freedom.

    American schools are not the only ones reporting success with stand-up desks. Four Catholic schools in Perth,Australia, which have been testing them since October 2013, have seen similar results. In May 2014, Grove House Primary School in Bradford, West Yorkshire,became Europe's first test one, with a seven-week trial that involved the useof desks made by Ergotron in their fifth-grade classrooms. While official results are not out yet, early reactions from both teachers and students, have been extremely encouraging.

    The findings of these studies and othersdone previously, all seem to mean that allowing kids to move around in classrooms is a win-win for students and teachers — it helps kids get healthier and provides educators with a more engaged audience.