搜题请搜索小程序“爱下问搜题”
问题 选择题

下列主题知识的归纳中，正确的一组是（　　）

 A．生活常识B．安全常识 
 用铁锅烹调食物→防止贫血

蛋白质摄入过少→使人生长发育迟缓

煤气泄漏→先打开排气扇

海鲜防腐→甲醛溶液浸泡 

C．物质鉴别 D．环保知识 
蚕丝布料和化纤布料→点燃

加碘食盐和无碘食盐→淀粉溶液 

臭氧层空洞→温室效应

过度施用农药、化肥→水污染和土壤板结 

A．生活常识

B．安全常识

C．物质鉴别

D．环保知识

答案

A、铁是合成血红蛋白的主要成分，缺铁会患贫血，用铁锅烹调可补充铁元素，所以正确；蛋白质是细胞的主要活性物质，是机体生长和修补受伤组织的原料，缺蛋白质会发育迟缓正确．

B、煤气有可燃性，与空气混合后，遇明火或电火花会发生爆炸，所以错误；甲醛有毒，能破坏蛋白质的结构，不能食用，所以错误．

C、蚕丝的主要成分是蛋白质，燃烧有焦糊味，化纤是合成纤维，燃烧有刺激性气味，所以正确；碘盐中的添加剂是碘酸钾，碘指碘元素，而不是碘单质，所以错误．

D、温室效应主要是大气中二氧化碳过量排放造成的，所以错误；化肥农药不合理施用会污染环境，破坏土壤结构，所以正确．

上述选项中A均正确．

故选A．

单项选择题

Dear Sirs,
Your shipment of twelve thousand ’Smart’ watches was received by our company this morning. However, we wish to make a number of complaints concerning the serious delay in delivery and your failure to carry out our specific instructions with regard to this order.
It was stressed from the beginning that the delivery date had to be less than six weeks from the initial order in order to meet our own customers’ requirements. While we understand that delays in production are occasionally inevitable, we must point out that the major reason why the order was placed with your company was because we were assured by you of its speed of delivery, and that your existing stocks were sufficiently high to ensure immediate shipment. Late delivery of the goods has caused US to disappoint several of our most valued customers, and is bound to have a negative effect on potential future orders.
The second complaint concerns the difference in color between the watches we ordered and those delivered. It was stated clearly in the original order that watches in combinations of green/purple and orange/purple only were required. However, only half the watches in the delivery received are of the colors specified. Our Hong Kong agent assures US that she stressed to you the importance of following our instructions precisely, since we consider there to be only a limited market in this country for watches of other colors at the present time. Any watches that are not of the specified colors will, of course, be returned to you.
We are also somewhat concerned about the rather poor quality of the goods received, since it is apparent that the watches that finally arrived have been produced from inferior materials and have been manufactured to a lower standard than those in the sample. We have also found that a number of the watches do not appear to be functioning. Whether the latter problem is due to poor manufacture, damage during transportation or bad batteries is not yet clear, but we should like to point out that we feel this matter to be entirely your responsibility.

Receiving watches in the wrong colors is a problem because ______.
A. the Hong Kong agent stressed the need to fulfill the order exactly
B. these watches will be difficult to sell
C. these watches will not be able to get into the limited market
D. people will not buy the watches as presents

As a result of the above problems, therefore, we feel that the most suitable course of action is to return to you unpaid any of the goods considered unsatisfactory, and to subtract any resultant costs from our final settlement. We shall also, of course, be forced to reconsider whether any further orders should be placed with your company.
We look forward to your prompt reply.


Yours sincerely,


John Smith
查看答案
多项选择题

心源性哮喘发生机制（）

A.睡眠时血液重新分配

B.气道高反应性

C.迷走神经张力增加

D.睡眠时横膈高位肺活量减少

E.气道炎症反应
查看答案