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【单选题】
食品保鲜膜按材质分为聚乙烯(PE)、聚氯乙烯(PVC)、聚偏二氯乙烯(PVDC)等种类。PVC被广泛用于食品、蔬菜的外包装，但它对人体有潜在危害。下列有关叙述中不正确的是( )A.
PVC保鲜膜属于链状聚合物，在高温时易熔化，能溶于酒精
B.
PVC的单体不能由PE的单体与氯化氢加成制得
C.
鉴别PE和PVC，可将其放入试管中加热，在试管口放置一湿润的蓝色石蕊试纸，如果试纸变红，则为PVC；不变红，则为PE
D.
等质量的聚乙烯和乙烯分别完全燃烧，聚乙烯消耗的氧气多
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【单选题】What does the word 'synaesthesia' refers to?
A.
It means that people may appreciate two kinds of beauty at the same time.
B.
It means that people may enjoy beauty with all senses at the same time.
C.
It holds that different spheres of senses may overlap.
D.
It is thoroughly studied by modem science.
【单选题】People can live for many days without food, but two or three days without water may ___ death
A.
result in
B.
result from
C.
carry away
D.
take away
【单选题】已知str_1 = '12345678dfggrytergrg',想获取最后3个元素,以下正确的是()。
A.
str_1[-3:]
B.
str_1[-4:]
C.
str_1[18:20]
D.
str_1[17:20]
【单选题】______ people went to the concert that was held in Reming Square _____ the night of May 25.
A.
Two thousands, on
B.
Many thousand, in
C.
Thousands of, on
D.
Several thousands of, in
【单选题】Attackers in China’s Xinjiang region crashed two cars into shoppers at a market in May, 31 people.
A.
killed
B.
to kill
C.
killing
D.
being killed
【简答题】You may meet many people in your life. But Mom and Dad are two of the most important people in your life. Over your lifetime, they may influence(影响) you more than anyone else you will meet. Moms and D...
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