Chinese mastered the technology of __________ approximately 5000 years ago. A: iron smelting B: metal smelting C: bronze smelting

Charcoal had been the main fuel of smelting and casting industry before ( ).

Chinese had mastered the technology of smelting bronze approximately 5,000 years ago and iron tools came into use during the ___________.

The _____ controlled the technique of smelting (冶炼) iron for 200 years and made iron weapons to attack its enemy. A: Hittites (赫梯人) B: Assyrians (亚述人) C: Persians (波斯人) D: Phoenicians (腓尼基人)

In the extremely long evolutionary process from the origin of humans, the final impacts and changes of food for the evolution of humans include ( ). A: application of fire make food from raw to cooked B: application of food processing tools make food from coarse to fine C: application of cooking utensils make food from simple to rich D: the emergence of bronzes and the development of smelting technology