[单选题]Few people seem to care about what a super star _____ before he/she became famous.A. goes through B. is going throughC. have gone through D. had gone through
[单选题]下列关于淀粉的认识中,不正确的是( )A.淀粉属于糖类,有甜味B.淀粉属于高分子化合物C.淀粉与碘水作用呈现蓝色D.淀粉在人体内能够水解,生成葡萄糖,经肠壁吸收进入血液
[单选题]下列关于药品使用的说法,错误的是 [ ]A.在注射青霉素之前,需要进行皮肤敏感试验 B.治感冒可用具有解热镇痛作用的阿司匹林 C.治疗由胃酸引起的胃痛,可用含有氢氧化铝等成分的抗酸药 D.经常失眠者可以长期大量服用安眠药
[单选题]By the time he realizes he _____ into a trap, itll be too late for him to do anything about it.[ ]A. walks B. walked C. has walked D. had walked
[单选题]-Have a rest. You ________ for a long time.-No. I have to make up for the missing lessons when I was ill.[ ]A.had readB.have been readingC.readD.will read
[单选题]2010年上海世博会的主题是“城市,让生活更美好”.下列叙述中不正确的是[ ]A.世博会前期,处理废水时加入明矾可作为混凝剂以吸附水中的悬浮物杂质且有杀菌消毒的作用 B.世博会期间,利用可降解的“玉米塑料”替代一次性饭盒,可防止产生白色污染 C.世博会中国馆--“东方之冠”使用的钢筋混凝土含大量水泥,水泥是硅酸盐材 D.世博停车场安装催化光解设施,可将汽车尾气中CO和NOx反应生成无毒气体
[单选题]下列说法不正确的是 [ ]A.高吸水性树脂属于功能高分子材料 B.食品包装袋、食物保鲜膜等材料的主要成份是聚乙烯 C.人造纤维、合成纤维和光导纤维都是有机高分子化合物 D.高分子化合物的结构大致可以分为线型结构、支链型结构和网状结构三类
[单选题]当液态空气温度升高达到刚沸腾时,在蒸发出的气体中 [ ]A.基本上不含氧气 B.氮气占体积的78% C.基本上不含氮气D.氮气含量稍高于体积的78%
[单选题]— How about buying Sam a mobile phone? A.ter all, he isnt a boy any more.— I think it necessary, for we sometimes want to make sure if he _______ home for dinner. [ ]A. will comeB. comes C. has come D. would come
[单选题]下列有关生活和生产中的化学知识描述不正确的是[ ]A.使用纤维素和淀粉为原料制成的微生物降解塑料,可治理“白色污染”B.发电厂的煤在燃烧时加入适量生石灰,有利于环境保护C.泄露在美国墨西哥湾海洋中的大量原油能被海洋生物迅速分解,不会导致生态灾难 D.大开发风能、太阳能、核能,有利于实现“低碳经济”,减少温室气体的排放
[单选题]广告称某品牌的八宝粥(含桂圆、红豆、糯米)不加糖,比加糖还甜,适合糖尿病人食用.你认为下列判断不正确的是 [ ]A.糖类不是都有甜味B.糖尿病人应少吃含糖的食品,该八宝粥未加糖,可以放心食用C.不加糖不等于没有糖,糖尿病人食用需慎重 D.不能听从厂商或广告商的宣传,应询问医生
[单选题]下列有关海水综合利用的说法正确的是( )A.利用电解的方法可以从海水中获取淡水B.海水中含有钾元素,只需经过物理变化就可以得到钾单质C.海水蒸发制海盐的过程只发生了化学变化 D.从海水中可以得到NaCl,电解熔融NaCl可制备Cl2
[单选题]绿色能源是指使用后不会对环境造成污染的能源,下列属于绿色能源的是( )(1)太阳能(2)风能(3)石油(4)煤(5)木材(6)潮汐能.A.(1)(2)(6)B.(2)(3)(4)C.(1)(2)(5)D.(2)(5)(6)
[多选题]对于合金的说法,正确的是A.常见的铜合金是青铜和黄铜B.合金与各组分金属相比具有更低的熔点C.钢是铁和碳的合金,生铁则是纯铁D.合金与各组分金属相比具有更大的硬度
[单选题]下列关于油脂氢化的说法不正确的是( )A.油脂的氢化是氧化反应 B.油脂的氢化是还原反应 C.油脂氢化后便于贮存和运输 D.油脂的氢化产物可用于制肥皂、甘油、人造奶油
[单选题]I was just going to cut my rose bushes but someone it. Was it you[ ]A. has done B. had done C. would doD. will do
[单选题]海洋有丰富的食品、矿产、能源、药物和水产资源等(如下图所示),根据下图海水 综合利用的工业流程图,下列说法不正确的是 [ ]A.从能量转换角度来看,框图中的氯碱工业是一个将电能转化为化学能的过程 B.过程②中结晶出的MgCl2·6H2O要在HCl氛围中加热脱水制得无水MgCl2C.过程①中除去粗盐中的SO42-、Ca2+、Mg2+、Fe3+等杂质,加入药品的顺序为:Na2CO3溶液→NaOH溶液→BaCl2溶液→过滤后加盐酸 D.在过程③、⑤中溴元素被氧化
[单选题]You should thank Peter. It was he who finally ____ your son to stop smoking and playing computer games.A.persuadedB.promised C.advisedD.suggested
[单选题]下列高聚物中,由两种不同的单体通过缩聚反应制得的是( )A.ECH2 CH2 CHCH23CNB.ECH2 CH-CHCH2 3C.ECH, CH-CHCH, CH, CH+D.OH-EO-CH2-CH,-0-C> >CoH
[单选题]— When did the computer crash— This morning, while I ________ the reading materials downloaded from some websites.[ ]A. have sortedB. was sortingC. am sortingD. had sorted
[单选题]— Isnt it a surprise that I happened to meet Emily at Doris birthday party last weekend— If my memory serves me correctly, you _________ each other for exactly three years.?[ ]A. hadnt seenB. havent seen C. didnt seeD. dont see