Why do pumice stone float on the surface of the water?
A: They are
comparatively smaller.
B: They contain special
materials.
C: They are not real stones.
D: There are pores in the stone.
A: They are
comparatively smaller.
B: They contain special
materials.
C: They are not real stones.
D: There are pores in the stone.
举一反三
- The reason why lotus leaves do not touch water is that the upper surface of lotus leaves is covered with many papillae which are smaller than rain water.
- How did “columnar joints” come into being? A: The magma condensed into stone columns. B: The pumice stones piles layer by layer. C: The volcanoes look like columnar joints. D: Creatures were gradually fossilized and they slowly turned into a thick limestone layer on the seabed
- Why did the Egyptians build the stone pyramids ?
- “Stone<br/>carving of a horse treading on a Hun” is the masterpiece of<br/>bronzes in the () Dynasty. A: Qin B: Zhou C: Han D: Northern
- You’ll<br/>trip ______ a stone if you don’t mind out.