题目

某同学在实验室中进行如下实验： 编号IIIIII实验装置现象没有明显变化，溶液仍为无色有白色沉淀生成，溶液为蓝色有无色气体放出以下结论正确的是 A． I中无明显变化，说明两溶液不反应 B． II中的白色沉淀为 CuCl2 C． III中的离子方程式为 2H+ +Zn=Zn2+ +H2 ↑ D． I中发生的反应不是离子反应 答案：C【详解】 A.硫酸和氢氧化钠反应生成硫酸钠和水，没有明显变化，故 A错误； B.硫酸铜和氯化钡反应生成白色硫酸钡沉淀和氯化铜，故 B错误； C.锌和盐酸反应生成氯化锌和氢气，离子方程式为 2H+ +Zn=Zn2+ +H2 ↑，故 C正确； D. I中发生的反应是离子反应，故 D错误。 故选 C。 “I‘m very tired from working here，”said Jean to her friend Kate， “ I’m on my feet from morning to night. For the first quarter of the day， I clean up the counter and set the tables. For the next quarter， I help in the kitchen. For the second half of my workday， I take orders at the counters.”  “Kate， I wish I had your job，”Jean went on. “For four hours you just sit at the cash register （收款台） taking in money.” “But I spend two more hours in the kitchen than you do，”said Kate. “It‘s tiring to cook over a hot stove. I don’t think you‘d really want my job. In fact， I’d like your job.” 1. Both Jean and Kate probably work in a ____________.  A. hotel        B. library          C. lab        D. shop 2. How long did they work every day？ _________.  A.  Eight  hours    B.  Twelve  hours.    C. Ten hours    D. Nine hours 3. How long did Kate spend in the kitchen？ __________.  A. A quarter day.    B. A half day.   C. One-third day.  D  Three-fourths day. 4. From this passage we can see that ____________.  A. they are both interested in their work.  B. their work is neither tiring nor busy. C. both of them are tired of their work.     D. they‘ve decided to give up their work. 5. Give a proper proverb （谚语） to Jean and Kate. A. It‘s never too late to learn     B. It‘s no use crying over spilt milk. C. The grass is always greener on the other side. D. One swallow（燕子）does not make a summer.