题目

实验室用乙酸、乙醇、浓硫酸制取乙酸乙酯，加热蒸馏后，在饱和Na2CO3溶液的液面上得到无色油状液体，当振荡混合物时，有气泡产生，主要原因可能是（） A . 有部分H2SO4被蒸馏出来 B . 有部分未反应的乙醇被蒸馏出来 C . 有部分未反应的乙酸被蒸馏出来 D . 有部分乙酸乙酯与碳酸钠反应 答案：C 阅读理解 　　Shu Pulong has helped at least 1000 people bitten by snakes．“It was seeing people with snake bites that led me to this career,”he said． 　　In 1963, after his army service, Shu entered a medical school and later became a doctor of Chinese medicine．As part of his studies he had to work in the mountains．There he often heard of people who had their arms and legs cut off after a snake bite in order to save their lives． 　　“I was greatly upset by the story of an old farmer I met．It was a very hot afternoon．The old man was pulling grass in his fields when he felt pain in his left hand．He at once realized he had been bitten by a poisonous snake．In no time he wrapped a cloth tightly around his arm to stop the poison spreading to his heart．Rushing home he shouted ‘Bring me the knife!’．Minutes later the man lost his arm forever．” 　　“The sad story touched me so much that I decided to devote myself to helping people bitten by snakes,”Shu said． (1) The best headline for this newspaper article is ________． [　　] A． Astonishing Medicine B． Farmer Loses Arm C． Dangerous Bites D． Snake Doctor (2) The farmer lost his arm because ________． [　　] A． the cloth was wrapped to tightly B． he cut it off to save his life C． Shu wasn’t there to help him D． he was alone in the fields (3) Shu decided to devote himself to snake medicine because ________． [　　] A． he wanted to save people’s arms and legs B． he had studied it at a medical school C． he had seen snakes biting people D． his army service had finished (4) Why did Shu go into the mountains? [　　] A． He wanted to study snake bites． B． He wanted to help the farmers． C． He was being trained to be a doctor． D． He was expected to serve in the army．