【单选题】【消耗次数:1】
700,000 new cars[填空] in India in the last twelve months.
have been sold
sold
sell
have sold
参考答案:
复制
纠错
相关题目
【单选题】 These goods are _____ for export, though a few of them may be sold on the home market.
①  essentially
②  completely
③  necessarily
④  remarkably
【单选题】 I have been at home [填空]Sunday.
①  on
②  for
③  at
④  since
【单选题】 A: Have you ever been to Huangshan? B:[填空].
①  No. Twice
②  I went there twice
③  Yes. Twice
④  Yes. Ill go there next month
【单选题】 The sandwhich course, [填空]I have been on for a week ,is really excellent.
①  which
②  that
③  whose
④  who
【单选题】 I came to?Beijing?in 1991 and have been ?[填空] here ever since.
①  live
②  lives
③  lived
④  living
【判断题】 答题说明:句子没有语法错误请选择“正确”,有语法错误请选择“错误”Once in a small village there was a young boy name John, whom sold cooking oil.
①  正确
②  错误
【单选题】 Areas where students have particular difficulty have been treated ____ particular care.
①  by
②  in
③  under
④  with
【单选题】 —How long have you been graduated from your college?— .
①  Yes, I’ve been graduated
②  I’ve been graduated for five years
③  I graduated from my college last year
④  I graduat from my college last year
【单选题】 – How long have you been graduated from your college?–
①  Yes, Ive been graduated.
②  Ive been graduated for five years.
③  I graduated from my college last year.
④  yes
【判断题】 A: How have you been? B: Fine.
①  正确
②  错误
随机题目
【单选题】 两个相邻斑点中心的距离与两个斑点的平均宽度(直径)的比值称为
①  比移值
②  Rf值
③  分离度
④  间距值
【单选题】 反相键合相色谱分离一化合物,若化合物分子中引入极性基团,则该化合物的K值
①  增加
②  减小
③  不变
④  无法判断
【单选题】 液-固色谱法属于
①  吸附色谱
②  分配色谱
③  离子交换色谱
④  分子排阻色谱
【单选题】 在纸色谱系统中分离极性物质时增加展开剂中极性溶剂的比例,极性物质的比移值如何变化
①  变小
②  变大
③  不变
④  无法判定
【单选题】 反相键合相色谱分离一化合物,若以乙腈-0.4%乙酸为流动相,减小乙腈的比例,则该化合物的容量因子K值和保留时间tR
①  K增加,tR减小
②  K减小,tR减小
③  K增加,tR增加
④  K减小,tR增加
【单选题】 下列不属于非极性键合相的是
①  ODS
②  苯基
③  辛烷基
④  氨基
【单选题】 在反相键合相色谱法中,常用的固定相是
①  硅胶
②  氧化铝
③  十八烷基硅烷键合硅胶
④  甲醇
【单选题】 薄层色谱在展开过程中极性较弱和沸点较低的溶剂,在薄层板边缘容易引起边缘效应,消除办法为
①  展开前应在展开缸中预饱和一段时间
②  展开过程中展开槽的盖子是打开的
③  薄层板在展开剂中浸泡一段时间
④  增加展开槽中展开剂的量
【单选题】 硅胶GF254的组成是
①  硅胶加12%~14%煅石膏
②  硅胶加黏合剂
③  硅胶不加黏合剂
④  硅胶加12%~14%煅石膏与荧光剂(在254nm紫外光下显强烈黄绿色荧光
【单选题】 氢火焰检测器的检测依据是
①  不同溶液折射率不同
②  被测组分对紫外光的选择性吸收
③  有机分子在氢火焰中发生电离
④  不同气体热导系数不同