1351
Q618507
If we add the prefix -UN to some words in English, we can get the opposite of that word, like in unwanted (l. 29). In this sense, consider the following words and analyze them:
I. able.
II. happy.
III. fair.
IV. acceptable.
Which of them can be an opposite just by adding the prefix -UN?
The sentence But constant negativity can also get in the way of happiness, add to our stress and worry level and ultimately damage our health.' (l. 02-04) could be paraphrased only by the following: 
The word help (l. 17) may be both a noun and a verb without having to change its spelling. The same may occur to all the words bellow, EXCEPT for: 
In the sentence taken from the text: The ability to recognize hand poses, for instance, will make it possible for people to interact with computers in new and more natural ways, such as communicating with computers simply by pointing at things, the underlined expression introduces: 
Segundo o depoimento da iraniana Sahar Zand, 
O assunto principal do texto NÃO envolve questões relacionadas à 