A new study shows that humans had the ability to make

A new study shows that humans had the ability to make
fire nearly 790,000 years ago,a skill that helped them migrate from Africa
to Europe.
By analysing flints at an archaeological site on the bank of the river
Jordan,researchers at Israel's Hebrew University discovered that early
civilizations had learned to light fires,a turning point that allowed them
to venture into unknown lands.
A previous study of the site published in 2004 showed that man had been able
to control fire -- for example transferring it by means of burning branches
-- in that early time period.But researchers now say that ancient man
could actually start fire,rather than relying on natural phenomena such as
lightning.
That independence helped promoted migration northward,they say.
The new study,published in a recent edition of Quaternary Science Reviews,
mapped 12 archaeological layers at Gesher Benot Yaaqov in northern Israel.
"The new data shows there was a continued,controlled use of fire through
many civilizations and that they were not dependent on natural fires,"
archaeologist Nira Alperson-Afil said on Sunday.
While they did not find remnants of ancient matches or lighters,Alperson-
Afil said the patterns of burnt flint found in the same place throughout 12
civilizations was evidence of fire-making ability,though the methods used
were unclear.
And because the site is located in the Jordan valley -- a key route between
Africa and Europe -- it provides evidence of the human migration,she said.
"Once they mastered fire to protect themselves from predators and provide
warmth and light,they were secure enough to move into and populate
unfamiliar territory," Alperson-Afil said.
1.Why was making fire so important for ancient people to explore new lands?(回答词数不超过15个）
2.What evidence made researchers think that human were able to make fire 790,000 years ago?回答词数不超过10个）
3.What couclusion has Nira's research group drawn?(回答词数不超过15个）