One medical text from the fourth century     1     using the extract from sweet wormwood to treat a fever. Tu’s team tested a collection of dried wormwood leaves but found no effect. They then tried     2     fresh wormwood, and using the liquid obtained from this to treat malaria, but this did not     3    either. Their project got    4    . However, Tu Youyou would not acknowledge     5    . She analysed the medical texts again, and by chance, she found one sentence suggesting a different way to treat the wormwood. She concluded that boiling the sweet wormwood     6     destroyed its medical properties. Using a lower    7     to draw out the extract, she found a substance that worked. After failing more than 190 times, the team finally succeeded in 1971. Tu Youyou and her team members even insisted     8    testing the medicine on themselves to make sure that it was     9    . Later, the medicine was tested on malaria patients, most of whom recovered. This medicine，which was called artemisinin, soon became a     10     treatment for malaria.