问题 选择题

下列“操作”与“现象”对应关系正确的是

 操作现象
A饱和食盐水中滴加少量浓盐酸,振荡溶液变浑浊
B饱和溶液中通入,振荡溶液变浑浊
C澄清石灰水中通入足量的,振荡溶液变浑浊
D氨水中滴加少量溶液,振荡溶液变浑浊

答案

答案:A

A中增大氯离子浓度,平衡向生成氯化钠的反应移动,正确。CO2和氯化钙溶液不反应,B不正确。C中应该是先出现白色沉淀,当CO2过量时碳酸钙又和CO2的水溶液反应生成碳酸氢钙,溶液澄清,不正确。D中氨水过量时,生成银氨溶液,得不到沉淀,不正确,答案选A。

完形填空

Some years ago, writing in my diary used to be a usual activity. I would return from school and   小题1: (spend) the expected half hour recording the day’s events, feelings, and impressions in my little blue diary. I did not really need to express my emotions by way of words, but I gained a certain satisfaction from seeing my experiences forever   小题2:  (record) on paper. After all, isn’t accumulating memories a way of preserving the past?

  When I was thirteen years old, I went on a long journey on foot in a great valley,   小题3:  (well-equip) with pens, a diary, and a camera. During the trip, I was busy recording every incident, name and place I came across. I felt proud to be spending my time   小题4:  (productive), dutifully preserving for future generations a detailed description of my travels. On my last night there, I wandered out of my tent, diary in hand. The sky was clear and lit by the glare of the moon, and the walls of the valley looked threatening behind their screen of shadows. I automatically took out my pen….

  At that point, I understood that nothing I   小题5: (write) could ever match or replace the few seconds I allowed myself to experience the dramatic beauty of the valley. All I remembered of the previous few days were the dull characterizations I   小题6:  (set) down in my diary.

  Now, I only write in my diary when I need to write down a special thought or feeling. I still love to record ideas and quotations that strike me in books, or observations that are particularly meaningful. I take pictures, but not very often—only of objects   小题7:  I find really beautiful. I’m no longer blindly satisfied with having something to remember when I grow old. I realize that life will simply pass me by if I stay behind the camera, busy   小题8:  (preserve) the present so as to live it in the future.

I don’t want to wake up one day and have nothing but a pile of pictures and notes. Maybe I won’t have as many exact representations of people and places; maybe I’ll forget certain facts, but at least the experiences will always remain inside me. I don’t live to make memories—I just live, and the memories form themselves.

单项选择题