There was a slight, but _____ air of disdain. A: imperceptible B: imperceptibly C: perceptible D: perceptibly

He will simply not listen to anybody; he is （） to argument. A: impervious B: imperceptible C: impassable D: blunt

"Here is a liquid as colourless as water, almost tasteless, quite imperceptible in coffee, wine, or any other beverage." In this sentece, "imperceptibble" means____ . A: indistinguishable B: noticeable C: strong

Scientists now find that such ____________ pictures can be made visible when people hear the name of the object in question. A: jettison B: disintegrated C: avert D: bountiful E: fabricate F: albeit G: deceleration H: imperceptible I: fragility J: insulation

中国大学MOOC: When one looks back upon the fifteen hundred years that are the life span of the English language, he should be able to notice a number of significant truths. The history of our language has always been a history of constant change—at times a slow, almost imperceptible change, at other times a violent collision between two languages. Our language has always been a living growing organism, it has never been static. Another significant truth that emerges from such a study is that language at all times has been the possession not of one class or group but of many. At one extreme it has been the property of the common, ignorant folk, who have used it in the daily business of their living, much as they have used their animals or the kitchen pots and pans. At the other extreme it has been the treasure of those who have respected it as an instrument and a sign of civilization, and who have struggled by writing it down to give it some permanence, order, dignity, and if possible, a little beauty. 　As we consider our changing language, we should note here two developments that are of special and immediate importance to us. One is that since the time of the Anglo-Saxons there has been an almost complete reversal of the different devices for showing the relationship of words in a sentence. Anglo-Saxon (old English) was a language of many inflections. Modern English has few inflections. We must now depend largely on word order and function words to convey the meanings that the older language did by means of changes in the forms of words. Function words, you should understand, are words such as prepositions, conjunctions, and a few others that are used primarily to show relationships among other words. A few inflections, however, have survived. And when some word inflections come into conflict with word order, there may be trouble for the users of the language, as we shall see later when we turn our attention to such maters as WHO or WHOM and ME or I. The second fact we must consider is that as language itself changes, our attitudes toward language forms change also. The eighteenth century, for example, produced from various sources a tendency to fix the language into patterns not always set in and grew, until at the present time there is a strong tendency to restudy and re-evaluate language practices in terms of the ways in which people speak and write.1.In contrast to the earlier linguists, modern linguists tend to _____________________.