[单选题]His first novel _____?good reviews since it came out last month.A. receives B. is receiving C. will receiveD. has received
[单选题]— How long have you________— It is about ten years since we________. [ ]A. married; marriedB. been married; were marriedC. got married; got marriedD. been married; got married
[单选题]在实验室中进行下列实验, 括号内的实验用品都能用到的是 [ ]A.硫酸铜晶体里结晶水含量的测定(坩埚、温度计、硫酸铜晶体)B.蛋白质的盐析(试管、醋酸铅溶液、鸡蛋白溶液)C.钠的颜色反应(铂丝、氯化钠溶液、稀盐酸)D.肥皂的制取(蒸发皿、玻璃棒、甘油)
[单选题]下列曲线是某环境监测小组几个成员分别描绘的某市中心空气中CO含量变化曲线.横坐标表示北京时间0时至24时,纵坐标表示CO含量.你认为比较符合实际的是[ ]A.B.C.D.
[单选题]下列说法正确的是A.NaCl常用于调味剂和防腐剂B.“西气东输”中的“气”指的是煤气C.食用纯碱可治疗胃酸过多D.无水乙醇常用作医用消毒剂
[单选题]向淀粉溶液中加少量稀H2SO4,加热使淀粉水解,为测其水解程度,需要的试剂是 ( )①NaOH溶液 ②银氨溶液 ③新制的Cu(OH)2悬浊液 ④碘水A.④B.②④C.①③④ D.③④
[单选题]有下列有机反应类型:①消去反应②水解反应③加聚反应④加成反应⑤还原反应⑥氧化反应.以丙醛为原料制取1,2-丙二醇,所需要进行的反应类型依次是[ ]A.⑥④②① B.⑤①④②C.①③②⑤ D.⑤②④①
[单选题]The country life he was used to _____ greatly since 2000. [ ]A. having changed B. has changedC. changing D. have changed
[单选题]自2008年6月1日起,在超市等场所禁用塑料袋.下列有关说法不正确的是( )A.少用塑料袋能保护环境B.少用塑料袋能节约资源C.塑料及其制品都属于混合物D.白色塑料造成了白色污染
[单选题]化学在绿色发展、循环发展、低碳发展及推进生态文明建设中正发挥着积极作用,下列做法与可持续发展宗旨相违背的是A.加大清洁能源的开发利用,提高资源的利用率B.用CO2合成聚碳酸酯可降解塑料,可以实现“碳”的循环利用C.加铅酸蓄电池、含汞锌锰干电池的生产,满足消费需求D.对工业废水、生活污水净化处理,减少污染物的排放
[单选题]食物的选择与其酸碱性关系很大.下列食物中,属于酸性食物的是[ ]A.柠檬 B.黄瓜 C.萝卜 D.鸡蛋
[单选题]下列说法正确的是( )A.石油的分馏和煤的干馏都是物理变化B.可用饱和碳酸钠溶液除去乙酸乙酯中混有的乙酸C.淀粉、纤维素的化学式都可表示为(C6Hl0O5)n,二者互为同分异构体D.淀粉、油脂和蛋白质都是高分子化合物
[单选题]在下列各有机物中,跟溴水、KMnO4酸性溶液、新制氢氧化铜悬浊液都能发生化学反应的是 [ ]A.CH2=CH2B.CH2=CH-CH2-OH C.CH2=CH -COOH D.CH3-CH2-CH2-CH3
[单选题]L-多巴是一种有机物,可用于帕金森综合症的治疗,其结构简式为,下列关于L-多巴的叙述不正确的是[ ]A.长期暴露在空气易变质B.既有酸性,又有碱性 C.一定条件下能发生聚合反应D.分子中只有6个碳原子共平面
[单选题]When I met Becky, she told me that she ______ for an interview the next day.A. would goB. has goneC. went D. had gone
[单选题]Dont phone me between 8 and 10 oclock. I my yoga class then. [ ]A. haveB. will be havingC. hadD. am having
[单选题]It is said in the book that Thomas Edison (1847-1931)? _____ the world leading inventor for sixty years . ( )A. would beB. has been C. had been D. was
[单选题]为改善空气质量而启动的“蓝天工程”得到了全民的支持.下列措施不利于“蓝天工程” 建设的是A.推广使用燃煤脱硫技术,防治SO2污染B.加大石油、煤炭的开采力度,增加化石燃料的供应量C.研制开发燃料电池汽车,减少机动车尾气污染D.实施绿化工程,防治扬尘污染
[单选题]— What did you do last Saturday, A.ex — Well , I ______to see a film , but in the end I stayed at home doing my homework.[ ]A. was goingB. has goneC. wentD. had gone
[单选题]下列说法不正确的是( )A.蔗糖不是淀粉水解的产物B.蔗糖的水解产物可能发生银镜反应C.蔗糖是多羟基的醛类化合物D.蔗糖与麦芽互为同分异构体
[单选题]某有机化合物B经过下列变化后可在一定条件下得到D,D能发生银镜反应.则有机物B是[ ]A.C2H5OHB.CH4C.HCHO D.CH3CHO