For the first time, scientists used saliva (唾液) to find the complete human genome (基因组) of an ancient woman, nicknamed Lola. Scientists did so based on a small piece of tree pitch (树节) that she chewed (咀嚼) some 5,700 years ago. They found the tree pitch, which is similar to gum, in Denmark. Scientists said Lola was likely to have had blue eyes, dark skin and hair. They also learned about the DNA of the food she had eaten and the microbes (微生物) inside her mouth.