问题
选择题
如图是一台显微镜的4个镜头,若要在视野中看到较多的细胞,应该选用目镜和物镜的组合是
A.①②
B.③④
C.①③
D.①④
答案
答案:D
题目分析:显微镜的成像的特点是呈放大的像,放大倍数=目镜倍数×物镜倍数,显微镜的放大倍数越大,看到的细胞数目越少,放大倍数越小,看到的细胞数目越多,所以选放大倍数最小的组合,选D。
如图是一台显微镜的4个镜头,若要在视野中看到较多的细胞,应该选用目镜和物镜的组合是
A.①②
B.③④
C.①③
D.①④
答案:D
题目分析:显微镜的成像的特点是呈放大的像,放大倍数=目镜倍数×物镜倍数,显微镜的放大倍数越大,看到的细胞数目越少,放大倍数越小,看到的细胞数目越多,所以选放大倍数最小的组合,选D。
选择句子,补全对话。 | |
A: Hi, Linda. Whose house is this? 1_____ B: Yes, it is. A: Oh, it's very nice. 2_____ B: There is a small garden. There are many trees in it. A: Oh, there are many trees beside the house, too. Wow! 3_____ B: You're right. On the first floor there is a living room and two bedrooms. On the second floor there is a kitchen, a dining room and a study. A: 4_____ B: There is a computer, a book case and a desk in the study. There are also some flowers on the table. A: 5_____ B: There are two pictures on it. A: Oh, I think it's good. I'll go to see it one day.
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