There are preemptive and non-preemptive approaches to handle critical section in operating system. As non-preemptive approaches doesn’t face problem of race conditions, explain in detail why we still use preemptive approaches to handle critical section.

Read this excerpt from helen keller’s autobiography, the story of my life. have you ever been at sea in a dense fog, when it seemed as if a tangible white darkness shut you in, and the great ship, tense and anxious, groped her way toward the shore with plummet and sounding-line, and you waited with beating heart for something to happen? i was like that ship before my education began, only i was without compass or sounding-line, and had no way of knowing how near the harbour was. "light! give me light! " was the wordless cry of my soul, and the light of love shone on me in that very hour. . the morning after my teacher came she led me into her room and gave me a doll. the little blind children at the perkins institution had sent it and laura bridgman had dressed it; but i did not know this until afterward. when i had played with it a little while, miss sullivan slowly spelled into my hand the word "d-o-l-l." i was at once interested in this finger play and tried to imitate it. when i finally succeeded in making the letters correctly i was flushed with childish pleasure and pride. running downstairs to my mother i held up my hand and made the letters for doll. i did not know that i was spelling a word or even that words existed; i was simply making my fingers go in monkey-like imitation. in the days that followed i learned to spell in this uncomprehending way a great many words, among them pin, hat, cup and a few verbs like sit, stand and walk. based on this excerpt, which words best describe helen keller?

Which statistical function in a spreadsheet you to see how far each number varies, on average, from the average value of the list?

Given a link with a maximum transmission rate of 32.8 mbps. only two computers, x and y, wish to transmit starting at time t = 0 seconds. computer x sends filex (4 mib) and computer y sends filey (244 kib), both starting at time t = 0. statistical multiplexing is used, with details as follows packet payload size = 1000 bytes packet header size = 24 bytes (overhead) ignore processing and queueing delays assume partial packets (packets consisting of less than 1000 bytes of data) are padded so that they are the same size as full packets. assume continuous alternating-packet transmission. computer x gets the transmission medium first. at what time (t = ? ) would filey finish transmitting? give answer in milliseconds, without units, and round to one decimal places (e.g. for an answer of 0.013777 seconds you would enter "13.8" without the quotes)