英语课前PPT.pptx

I Can't Blieve It
Which is not ture?
There are many colourful lake
Made By Photoshop
Jiuzhaigou
The rock surrounding the lake is purple and pink. While the glacier(冰川) is melting (融化),the pink grains will dissolve (溶解) in the water and flow into the ice-cream-colour lake.
Peaple used to think that the pink colour came from a kind of plant in the water which can produce carotenes(胡萝卜素). But now some scientists find they were wrong and leave it still a secret.
Which are not ice and snow?
CH4
When bacterias(细菌) break down the dead creatures,CH4 is released and imprisoned in the ice .Then,it will look like a string of bubbles(泡泡) .
This fantastic scene was shot in the ocean of the arctic circle (北极圈).It is produced from the huge differe--nce in temperature between the ocean and the atmosphere.
The ugly white trees is caused by some s.
After a flood in Pakistan, many spiders climbed up the trees to avoid being that,they spined white webs(结网) on the thees.
Water overflows from the trunks which are influenced by some bacterias (细菌).
This is frost(霜花) . Though it looks pure, there are a lot of bacterias inside it.