Oolong tea, made from more mature leaves, usually have less caffeine than green tea. On the flip side, mature leaves contain less theanine, a sweet, natural relaxant that makes a tea much less caffeinated than it actually is. That is the theory, anyway.
The highest point in Asia is Mt. Everest which is 8,850 meters above sea level. And Asia's lowest point is the Dead Sea which is 400 meters below sea level.
North-west China is covered in desert. In the very far north-east, close to Russia, the temperature can drop to -50ÂºC in the winter. In the west of China there are the Himalayas, with some of the highest mountains in the world. China's lowest point is in the Turfan Depression, at -154 metres below sea level.