题干

下列各种生理作用中,属于非特异性免疫的是(       )

①体液中的杀菌作用    

②吞噬作用      

③免疫细胞产生抗体

④皮肤和黏液的屏障作用      

⑤黏膜的杀菌作用

A:①②③⑤

B:①②④⑤

C:①③④⑤

D:②③④⑤

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答案(点此获取答案解析)

B

同类题3

阅读下面这篇文章,完成下列小题。

寻春

    ①迎着早春的轻寒,或野游,或山行,多么好啊。也许,早春的景色过于素淡了;可也正因为还没有万紫千红的撩拨,才更宜于漫步、沉思……

    ②趁个假日,我出了城,径自寻春去了。

    ③“山带去年雪,春来何处峰?”眼前,蓟塞披沙,燕山负雪,该上哪里去寻春呢?又寻春的什么呢?……嗯,春的影子么,该是绿的。如果找见了大地上最初的一小片草地,那就一定是春天刚刚落脚的地方。春天必在那里。

    ④不上田间小路,我只朝着旷野走去。

    ⑤微风挟着寒意,卷地而来。这大概是朔气的余威了。“燕北地寒生草迟”,低眉所见,尽是些隔冬的衰草,谁知有没有一两株敢于破土而出的小草?即使有,怕也不易找见……

    ⑥穿疏林,过小桥,桥下流水无声,慢吞吞的,仿佛刚才融没了最后一片残冰,那满怀凝冻的迟疑,还没散尽……我不禁责怪起自己来:虽说是早春之游,也未免太早了。但是,既来之,则安之——走吧。

    ⑦渐渐地,云雾中的山峰越来越清晰了。到了山脚下,有大石如卧。近前转身坐定了,无意间,向着来路抬眼一望……怎么?远处,小桥头,疏林边,那旷地上,竟泛出一片新绿!仔细看去,还含着几分鹅黄——好嫩,好新鲜。可那旷地,分明是我才经过的,来时没见一芽新草。莫非不早不迟,正当我才上了小桥那阵儿,就在我背后,春天,悄悄儿地飞落在林边了?……我猛地站起来,朝着那片草色奔去。

    ⑧小桥下,流水依然迟迟的;林边旷地,又在脚下了。仍旧是几许衰草,一带疏林。莫不是春天怕这里寒肃,刚落脚,竟又携着她那青青的影子,一同飞去了?

    ⑨哦,这不正是“草色遥看近却无”!

    ⑩重又跑回山脚下,大石跟前;转身再放眼望去,可不,那疏林边,草色依稀,似乎比刚才又浓了些,也扩展了些。“草色遥看近却无”。这早春草色,为什么只可遥看呢?回想一路所见——是了,说是来寻春,却只低眉顺目,眼界自然仅限于咫尺间了。“燕草如碧丝”,走三五步难见一两芽,何况还有衰草杂陈呢。若是放眼望去,那些萌芽,就算是一个个微绿的质点吧,那么,这十里平川,尽收眼底,那质点,也该不可胜数了。无数个微绿的质点,横行纵漫,就密了,草色也浓了——瞧那边,好一抹新绿。衰草的憔悴,被欣欣然的生机淹没了。

    ⑪一霎间,这一抹新绿似乎浸润了我的全身,染绿了我的每一个细胞。我似乎寻到了春天的步履。

    ⑫真的,就连野游,都需要扬眉放眼,才能从无数点刚刚破土的萌芽上面,看到无边的春色。那么,对于生活呢……在人生的道路上,在斗争的历程中,总会有阴霾、霜雪,但是,尽管朔气如磐,时间却没有一瞬的凝固。“今朝腊月春意动”。这是诗意,也是万古不灭的规律。而正当风雪弥天的时刻,谁能在胸怀深处寻到那最初的一抹新绿,用自己的心去暖它,催促它,谁就会拥有一个芳草连天、艳阳满地的内心世界。心里有一个春天,那就往前走吧。诗云“燕山雪花大如席”,哪怕真是“大如席”的燕山雪花砸到热腾腾的胸膛上,也将立刻消融。如果谁的内心的春光与大地上第一抹草色连成一片了,那就把步子迈得再大些。这样的步子,每一落地,都会铿锵作响;路旁的花蕾呢,也将应声怒放。

同类题4

阅读理解

    As if 2016 hadn't been hard enough for China's workforce, a yearly survey has revealed that more than half of the country's white-collar employees got no year-end bonus ahead of the upcoming and costly lunar(农历的) New Year holiday. The survey of 11,500 workers by Chinese employment agency Zhaopin found that 50.9 per cent did not get an annual bonus at the end of 2016. Another 9.6 percent were told their bonuses had been delayed until after the New Year holiday.

    Before the slowdown that began in 2014, employers in China had been less ungenerous with cash bonuses, which can total well over a full month's pay and send employees back home for the holiday with plenty of cash for gifts to elders and other family members or to put away as savings. The impact of weak growth on year-end bonuses may have reached the highest point in 2015, however, when 66 per cent of white-collar workers received no year-end bonuses. And the 2016 level actually represents an improvement from 2014, when 61 per cent had to go without.

    But that recovery has also seen the size of bonuses drop: last year the average bonus was Rmb 12,821($1,861), about Rmb 2,000 more than that in 2015 but still about Rmb800 below the 2014 average. More than a quarter of those surveyed who saw their bonuses drop last year blamed the drop on poor company performance.

    Differences among the 34 cities surveyed were still greater, as the average bonus of over Rmb 15,800 in Beijing was more than three times than that in the lowest-paying city of Shenyang. Employees of state-owned firms also expressed more satisfaction with their bonuses than those at private companies — and little wonder, as the average bonus at the former was Rmb 17,318, or about Rmb 6,000 more than what private companies' employees could expect.

    But the impact of companies' stinginess(吝啬) can go beyond simply ruining employees' New Year holiday, possibly coming back to affect employers: 39 percent of respondents said they would look for work elsewhere if their year-end bonus was not returned to normal, an increase of 2.3 Percentage points from 2015.