题干

几个同学在有充足光线的实验室用显微镜观察一个自己制作的植物玻片标本时,发现视野中一片黑暗。请你分析出现这种情况可能的原因有哪些?(提示:可联系显微镜的使用、玻片标本的制作等)可能的原因:①____。②____。③____

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\u540c\u5b66\u4eec\u56f4\u7740\u663e\u5fae\u955c\uff0c\u6321\u4f4f\u4e86\u5149\u7ebf,\u8f6c\u6362\u5668\u4f4d\u7f6e\u6ca1\u6709\u8c03\u597d\uff0c\u6b66\u8b66\u6ca1\u6709\u5bf9\u51c6\u901a\u5149\u5b54,\u690d\u7269\u73bb\u7247\u6807\u672c\u5236\u4f5c\

同类题1

阅读下面短文,按要求完成各项任务。

    I went through some difficult times, dealing with the pressures of growing up. I found it hard to communicate with my mother. Relations between us became difficult.

    One day, I ran away from home and stayed away for many hours. When I returned home at night, I saw all the pain, anger and disappointment on my mother’s face. ①      . We agreed to have breakfast together the next morning. It was a turning point in both of our lives and our relationship.

We decided to go to a restaurant. On our way to the table I noticed my mother had two notebooks. I asked her what they were for. She explained to me that sometimes it was easier to write down our feelings rather than talk about (A) them. We would write down our feelings in the form of a letter. It could be as long or as short as we wanted.

    Our first topic was “Why I'm so angry?” I wrote a half page, and my mom filled up nearly three pages. (B) I watched tears run down her face as she wrote. I never realized anyone could hide so much anger. After we finished writing, we exchanged our notebooks. As soon as I started reading my mother's words, I began to cry and so did she. When we finished reading, we discussed our feelings. ②      . Our talk helped me realize so many things I had never thought of before, not only about my mother but also about other people.

     My mother and I continue to use our notebooks as a way of communicating our anger and worries, and our happiness as well. We know that no matter how we feel about each other, our notebooks are a safe place to express our feelings. We have come to an agreement that at the end of each letter we write, “I love you.”