A:在光线比较暗的实验室内使用显微镜时,应调大光圈,用凹面反光镜
B:使用显微镜进行观察,使镜筒下降时,眼睛要注视目镜
C:在显微镜下看到了“b”,实际在载玻片上的是“q”
D:低倍镜下观察到的细胞物像模糊时,可转动转换器换成高倍镜进行观察
Last year, some groups of students in their community (社区) made a survey about “How do people spend their free time? ” The following diagrams(图表) show some results of it: Diagram (1): Hours for people of different ages who surf the Internet in a week. Diagram (2): Different days people go to the library. (library attendance)
Diagram (3): Different programs people like.
3%的硼酸溶液可用于清洗皮肤的小面积创伤.现配制300g质量分数为3%的硼酸溶液,实验操作如下:
(1)称量硼酸固体的质量:在如图1中分别标出①②所选砝码的质量和游码的示数____ .
(2)量取水的体积:用量筒取 ____ mL水().
(3)装瓶、贴标签:在如图2的标签中填上相应的内容____ .
正常人体内的激素、酶和神经递质均有特定的生物活性,这三类物质都是 ( )
下列关于细菌、真菌与人类生活关系的叙述中,正确的是( )