问题 解答题

某生物兴趣小组的同学为研究植物的生命活动,设计了以下实验装置,请据图分析回答(注:氢氧化钠溶液可以吸收二氧化碳):

(1)首先将甲、乙两个装置放在黑暗处一昼夜,然后将甲、乙装置放在光下照射几小时,从甲装置和乙装置中各取一片叶,经酒精脱色后,滴加碘液,变蓝色的是______装置中的叶片.此实验现象可以证明______是光合作用的原料.

(2)如果乙装置中的清水换成澄清的石灰水,要使澄清的石灰水变混浊,乙装置必须放在______环境中,其目的是防止植物进行______.

(3)在实验过程中,玻璃罩内壁出现的水珠主要来自植物的______,水分是通过叶片上的______散失的.

答案

(1)实验前应将甲、乙两个装置放在黑暗处一昼夜,目的是让叶片内原有的淀粉运走耗尽;光照几小时后,从甲装置和乙装置中各取一片叶,经酒精脱色后,滴加碘液,变蓝色的是乙装置的叶片,因为乙装置中含有光合作用的原料二氧化碳,因此乙装置中的绿色植物进行了光合作用,而甲装置中的二氧化碳被小烧杯里的氢氧化钠吸收了,由于没有进行光合作用的原料,因此甲装置中的植物没有进行光合作用;比较甲、乙装置的实验现象,可以得出结论:二氧化碳是光合作用的原料.

(2)植物的光合作用需要光,在黑暗环境中植物只进行呼吸作用,若要使乙装置中的清澄清的石灰水变混浊,则应将乙装置放在黑暗环境中,目的就是防止植物进行光合作用而影响实验现象的产生.

(3)水分以气体状态通过叶片表皮上的气孔从植物体内散失到植物体外的过程叫做蒸腾作用,实验过程中植物进行蒸腾作用散失的水分会凝结在玻璃罩内壁上.

故答案为:(1)乙;二氧化碳 

(2)黑暗;光合作用  

(3)蒸腾作用;气孔

问答题 简答题
单项选择题

"The impulse to excess among young Britons remains as powerful as ever, but the force that used to keep the impulse in check has all but disappeared," claimed a newspaper. Legislation that made it easier to get hold of a drink was "an Act for the increase of drunkenness and immorality", asserted a politician.

The first statement comes from 2005, the second from 1830. On both occasions, the object of scorn was a parliamentary bill that promised to sweep away " antiquated" licensing laws. As liberal regulations came into force this week, Britons on both sides of the debate unwittingly followed a 19th-century script.

Reformers then, as now, took a benign view of human nature. Make booze cheaper and more readily available, said the liberalisers, and drinkers would develop sensible, continental European-style ways. Nonsense, retorted the critics. Habits are hard to change; if Britons can drink easily, they will drink more.

Worryingly for modern advocates of liberalisation, earlier doomsayers turned out to be right. Between 1820 and 1840, consumption of malt (which is used to make beer) increased by more than 50%. Worse, Britons developed a keener taste for what Thomas Carlyle called "liquid madness"—gin and other spirits.

The backlash was fierce. Critics pointed to widespread debauchery in the more disreputable sections of the working class. They were particularly worried about the people who, in a later age, came to be known as "ladettes". An acute fear, says Virginia Berridge, who studies temperance at the London School of Hygiene and Tropical Medicine, was that women would pass on their sinful ways to their children.

In the 19th century, temperance organisations set up their own newspapers to educate the public about the consequences of excess. That, at least, has changed: these days, the mainstream media rail against the demon drink all by themselves.

It can be inferred from the second paragraph that()

A. the dispute over alcohol licensing has overtones of 19th-century arguments

B. Britons developed a keener taste for gin and other spirits

C. sinful ways would be passed on by women to their children

D. the public should be educated about the consequences of excess