题干

下列实验操作中,正确的是                      

A:配制5%NaCl溶液时,将称量的NaCl放入烧杯中加计量的水搅拌溶解

B:蒸馏操作时,应将温度计插入烧瓶中的溶液中

C:测溶液的pH时,将pH试纸放入溶液中观察其颜色变化,跟标准比色卡比较

D:分液操作时,先将分液漏斗中的下层液体放出,然后再将上层液体放出

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A

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    My transportation was unexpectedly smooth and I arrived at the meeting half an hour earlier. I kept my eyes on the restaurant door. Several customers entered, but not my friend. At 6:00 pm, she sent me a text message:“Urgent work to finish. Will be 20 minutes late.”

I had left my book in the office, so I spent the time thinking of my experiences of being late in China. On my first visit in 1985, punctuality was deeply rooted in the Chinese hearts. There were no traffic jams then.

    As a teacher in Canada, I always insisted on punctuality. I would open the classroom door to a late student for the first time and the second, but not the third. During the six years I worked for CCTV, I had a Chinese friend whom I often saw at lunch time, or after work. We used to meet at the subway station nearby. He was always late by 10-20 minutes. To myquestion, “You were busy?” he would surprisingly answer, “ No.” Once I asked him to check the clock in his office, he smiled.

    In March 2015, I got permanent residence (居住权) in China.The ceremony was scheduled for 9:00 am at the Public Security Bureau on the Second Ring Road. I told my driver I had to get there by 8: 40 am. “No problem,”he replied. But he thought he had time to drop someone off at the airport before picking me up. I desperately waited for him. Then, to rub salt into my wound, he had to stop at the exit of a gas station. Finally, I entered the room at 9:07 am ── the last guest to arrive!