问题 填空题

(15分)

(1)(3分)现有下列物质:维生素A、维生素C、碘元素、铁元素、淀粉、油脂。请选择正确答案填在相应的空格里。

①人体缺乏某种维生素会引起坏血病,这种维生素是__             __

②人体缺乏某种微量元素会发生贫血,这种微量元素是____            __

③既能为人体提供热量,又能提供必需脂肪酸的物质是____          ____

(2)(5分)了解一些用药常识,有利于自我保健。现有下列药物:碳酸镁、青霉素、阿司匹林、氢氧化铝。

①其中属于解热镇痛的药物是___          ___

②青霉素的作用是__            _

③碳酸镁可治疗胃酸过多的原理是                   (用离子方程表示)。

④药片常用淀粉作为黏合剂,淀粉水解的最终产物是____          ____

(3)(7分)生活中处处有化学,化学已渗透到我们的“衣、食、住、行”之中。

①衣:鉴别真假羊毛衫的方法是先取样,再__                      __

②食:水是人类生存的必需物质。在净水过程中,明矾作为             剂;氯气或漂白粉作为             剂。

③住:玻璃和钢铁是常用的建筑材料。普通玻璃是由___         ____等物质组成的;钢铁制品不仅可发生化学腐蚀,在潮湿的空气中还能发生____        ____腐蚀。

④行:铝可用于制造交通工具,铝制品不易生锈的原因是____   ____;橡胶是制造轮胎的重要原料,天然橡胶通过____      _____措施可增大强度和弹性。

答案

(15分)

(1)(3分)①维生素C   ②铁元素   ③油脂

(2)①阿司匹林    ②消炎杀菌    ③MgCO3+2H+==Mg2++H2O+CO2↑    ④葡萄糖

(3)(7分)①灼烧,若有烧焦羽毛气味,则为真羊毛衫

②混凝   杀菌消毒

③Na2SiO3、CaSiO3、SiO2 ;   电化学

④表面被氧化生成一层致密的氧化物保护膜;   硫化

选择题
单项选择题

About fifty years ago, plant physiologists set out to grow roots by themselves in solutions in laboratory flasks. The scientists found that the nutrition of isolated roots was quite simple. They required sugar and the usual minerals and vitamins. However, they did not require organic nitrogen compounds. These roots got along fine on mineral inorganic nitrogen. Roots are capable of making their own proteins and other organic compounds. These activities by roots require energy, of course. The process of respiration uses sugar to make the high energy compound ATP, which drives the biochemical reactions. Respiration also requires oxygen. Highly active roots require a good deal of oxygen.
The study of isolated roots has provided an understanding of the relationship between shoots and roots in intact plants. The leaves of the shoots provide the roots with sugar and vitamins, and the roots provide the shoots with water and minerals. In addition, roots can provide the shoots with organic nitrogen compounds. This comes in handy for the growth of buds in the early spring when leaves are not yet functioning. Once leaves begin photosynthesizing, they produce protein, but only mature leaves can "export" protein to the rest of the plant in the form of amino acids.

What is the main topic of the passage

A.The relationship between a plant’s roots and its shoots.

B.What can be learned by growing roots in isolation.

C.How plants can be grown without roots.

D.What elements are necessary for the growth of plants.