摘要:2.表示某动作从过去开始发生.持续到现在.并且还有可能持续下去.常用的时间状语有today, this week, these days, so far, up to now, since, ever since, since then, by this time, for years / ages, for a long time, several times, in / over the past few years, “since + 过去某一时刻 ,“for + 时间段 等.有时在时间或条件状语从句中.可用现在完成时代替将来完成时. [考例]Hearing that she the entrance exam to the university.Fudy is thrilled.[青岛市] A.has failed in B. is succeeded in C.is failed in D.has succeed in [答案]D.[解析]本题考查词义辨析 由“听说他成功地通过了考试.Judy非常兴奋. 可知选D. --It's raining! When did it start? 一I don't know exactly.In fact.it all this afternoon. [北京市] A1asts B has 1asted C.1asted D.will 1ast [答案]B.[解析]考查现在完成时态.从句意“事实上.已持续了整整一个下午了 .不难看出.不能用一般过去时.此句中last"持续 作延续性动词.从信息"all this afternoon"可知. --Are you going to see the film with us? --No, thanks. I it. [广东省] A. saw B. have seen C. see D. was seeing [答案]B.[解析]本题考查动词的时态.由对话的语境可推测句意“我已看过这部电影 .表示过去发生的动作对现在造成的影响或结果.故应用现在完成时. --Hello, this is Lily speaking. Could I speak to Mr. Black? --Sorry. He the Xuanwu Lake Park. [南京市] A. has been to B. went to C. has gone to D. will go to [答案]C.[解析] 考查现在完成时态.have gone to(到某地去了.还没有回来),have been to. Jane . I'm waiting for her. [成都市] A. came back B. has come back C. hasn't come back [答案]C.[解析]考查现在完成时态.根据后句句意:“我正在等她 可知.

网址:http://m.1010jiajiao.com/timu3_id_2431359[举报]

(每空1分,)如图甲表示某生物膜结构,图中A、B、C、D、E、F表示某些物质,a、b、c、d表示物质跨膜运输方式。图乙和图丙表示物质运输曲线,请据图回答:

(1)A代表        分子,B代表           ,D代表           
(2)动物细胞吸水膨胀时B的厚度变小,说明B具有                 
(3)维生素D和葡萄糖从肠腔进入小肠上皮细胞的过程分别是图中编号          
(4)若图甲是癌细胞的细胞膜,则膜上含量较正常细胞减小的物质是[   ]        
(5)若图中是线粒体膜,b和c过程运输的气体分别是          。b、c运输方式符号图         所表示的物质运输曲线。
(6)若图甲表示人体红细胞膜,则表示Na、K运输的分别是图中        。Na、K的运输方式符合图中          所示曲线。
(7)已知红细胞吸收葡萄糖是协助扩散,而有人认为小肠上皮细胞以主动运输的方式吸收葡萄糖,请设计实验加以确定。
①实验步骤:
第一步:取甲、乙两组生长状况相同的小肠上皮细胞,放入适宜浓度的含有葡萄糖的培养液中。
第二步:甲组细胞给予正常的呼吸条件,                                
第三步:                                                            
②预测实验结果并分析:
a.若甲、乙两组细胞对葡萄糖的吸收速率基本相同,则                   
b.                                                                 
查看习题详情和答案>>

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网