2011年6月6日端午节,小玲在爷爷家看到伯父的眼镜很漂亮,于是她拿着伯父的眼镜靠近“早餐饼干”的包装盒,看到了如图的情景,则下列说法正确的是( )
A:该镜片是凸透镜,对光有会聚作用,可用来矫正远视眼
B:该镜片是凹透镜,对光有发散作用,可用来矫正近视眼
C:伯父是近视眼,不戴眼镜看远处物体时,像成在视网膜后
D:伯父是远视眼,不戴眼镜看近处物体时,像成在视网膜前
①画出图1向下平移4格后的图形。
②画出图2向左平移6格后的图形。
③画出梯形向右平移8格后的图形。
根据短文理解选择正确答案。
Here is a timetable of science activities in the Children's Palace of Xiangtan city.
Timetable
Monday
Space and Man(1 weeks)
19: 00—21: 30
Dr. Li Bin (Hunan Science and Technology University)
Would you like to know more about the outer space?
Thursday
Modern Medicine(4 weeks)
19: 00—21: 00
Dr. Zhu Jiankang (Xiangtan Central Hospital)
Would you like to know medical advances(进步)?
Tuesday
Photography(5 weeks)
18: 30—20: 30
Mr. Chen Yi, from Xiangtan Daily, will show you how to take good pictures. Please bring your own camera.
Saturday
Technical English(16 weeks)
14: 00—17: 00
Dr. Rose White Do you want to learn the technical words and articles?
Wednesday
Computer Science
18: 30—21: 00
Prof. Han Lin from Xiangtan University Learn how to use Office 2010.(3 weeks)
Sunday
Exhibition(展览)of Personal Inventions
8: 30—11: 30
You can see many inventions by the students; you may also bring your own inventions.(2 weeks)
在一个无色大塑料瓶的侧壁靠底部的位置钻一个小孔,用胶带粘住小孔,在瓶中装满水,在瓶的另一侧放一只激光电筒,调节光束的方向,让光束正好能射中对侧的小孔(如图所示).揭下胶带,让水流到下面的盆里,你会看到光随弯弯的水流照到盆底,在盆底产生一个光斑.
下列说法正确的是( )
通过对实验现象的观察、分析、推理得出正确的结论是化学学习的方法之一,下列对各实验事实的解释正确的是( )
选项
现象
解释
A
氯水使有色布条褪色
次氯酸具有强氧化性
B
蔗糖中加入浓硫酸时蔗糖变黑
浓硫酸具有吸水性
C
SO2气体使品红溶液褪色
SO2具有强还原性
D
铜片放入浓硫酸中,无明显变化
铜在冷的浓硫酸中发生钝化