题干

试管内壁残留下列物质,用稀盐酸浸泡不能除去的是(   )

A:用足量H2还原氧化铜后留下的红色物质

B:用足量CO还原氧化铁后留下的黑色物质

C:长时间盛放石灰水后留下的白色固体

D:氢氧化钠溶液和硫酸铁溶液反应后留下的红褐色固体

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A

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      As a child, I started learning to play the piano, my favorite musical  1 ,but I was forced to give up when I started my middle school  2  I could concentrate more on my studies.
      It’s one of my biggest  3  to stop practicing the piano when I recall sadly today. During the following years, I kept telling my piano teacher that I would  4  . However, I didn’t keep my promise because I was 5  with my study.  6  I lost touch with my teacher. Some years later, my teacher died. I was very sad because I lost such a good teacher. She was a very warm and gentle person. It hurts me to think she may have been 7  that I never returned. I haven't taken lessons since then but to be honest, I  8  to. Sitting at the piano, I couldn't help recalling  many  9  times of my practising at home and playing before my teacher and one time my teacher 10  me after I played entire pieces of music wrong in front of her colleagues. I was so  11  that I could hardly say anything. But her  12  helped me ease my shame. These memories, 13, good or bad, never caused my  14  for playing the piano again.
      This thought then led me to think that  15 is like music, and that we all try to play different  16  in the instrument of our life. Sometimes the pitch(音高) is    17 when we play it well, but sometimes we are out of tone. However, we all continue to create our own  18  style of music. No matter what style our music is, it is  19 that we sing the songs of joy, quietness and love. Though I may never make it back to piano lessons, it doesn’t  20  that I’ve stopped making music.