搜题请搜索小程序“爱下问搜题”
问题 多选题

近日美国有研究发现，有些品牌的牙膏在使用过程中和用氯消毒过的水接触后会产生“哥罗芳”．长期使用可致癌，在社会上引起极大的反响．后经进一步研究证明其中含量极小对人不一定会构成危害．“哥罗芳”是三氯甲烷的俗名，其化学式为CHCl3下列关于它的说法中不正确的是（　　）

A．“哥罗芳”是一种有机物

B．“哥罗芳”是由碳原子、氢原子、氯原子构成的

C．“哥罗芳”中碳元索、氢元素、氯元素的质量比为l：l：3

D．“哥罗芳”的相对分子质量为119.5

答案

BC

填空题

溴麝香草酚蓝溶液是一种指示剂，较低浓度的CO2使其由蓝变绿，较高浓度CO2使其由蓝变绿再变黄．一实验小组用图示的实验装置在25℃条件下，多次进行如下操作：①打开阀门A和B、推注射器1的活塞，然后关闭A和B．②一段时间后，拉注射器2的活塞，促进两个瓶中的气体流动．观察溴麝香草酚蓝溶液的变色情况．（阀门A和B关闭时，整个装置是密封的）

请完成下列问题：

（1）此实验的目的是______

（2）如果向苹果瓶中注入一定量的N2，一段时间后溴麝香草酚蓝溶液几乎不变色．这种情况下苹果的代谢特点是______；

（3）当向苹果瓶内注入的氮气很少或很多时，溴麝香草酚蓝溶液将会变黄，其原因是：______

（4）此实验结果可在于实际生活中用于______，理由是______．
查看答案
单项选择题

Starting with his review of Skinner’s Verbal Behavior, Noam Chomsky had led the psycholinguists who argue that man has developed an innate (天生的) capacity for dealing with the linguistic universals common to all languages. Experience and learning then provide only information about the (1) instances of those universal aspects of language which are needed to communicate with other people within a particular language (2) .

This linguistic approach (3) the view that language is built upon learned associations between words. What is learned is not strings of words per se (本身), but (4) rules that enable a speaker to (5) an infinite variety of novel sentences. (6) single words are learned as concepts: they do not stand in a one-to-one (7) with the particular thing signified, but (8) all members of a general class.

This view of the innate aspect of language learning is at first not readily (9) into existing psychological frameworks and (10) a challenge that has stimulated much thought and new research directions. Chomsky argues that a precondition for language development is the existence of certain principles "intrinsic (原有的) to the mind" that provide invariant structures (11) perceiving, learning and thinking. Language (12) all of these processes; thus its study (13) our theories of knowledge in general.

Basic to this model of language is the notion that a child’s learning of language is a kind of theory (14) . It’s thought to be accomplished (15) explicit instruction, (16) of intelligence level, at an early age when he is not capable of other complex (17) or motor achievements, and with relatively little reliable data to go on. (18) , the child constructs a theory of an ideal language which has broad (19) power. Chomsky argues that all children could not develop the same basic theory (20) it not for the innate existence of properties of mental organization which limit the possible properties of languages.

2（）

A.region

B.district

C.vicinity

D.community
查看答案