Read the text carefully and then choose the correct answers.Years ago, because of the lack of good medical care, diseases were the most terrible threat to the early people. Of course, they had no pills, tablets or capsules as we do today. They used to eat herbs or three bark to cure many diseases. They also knew that food had great effect on their health. Actually the medicines that we take today are mostly extracted from herbs, tree bark, plants and food. For example, in the 17th century, the ...

Read the text carefully and then choose the correct answers.

Years ago, because of the lack of good medical care, diseases were the most terrible threat to the early people. Of course, they had no pills, tablets or capsules as we do today. They used to eat herbs or three bark to cure many diseases. They also knew that food had great effect on their health. Actually the medicines that we take today are mostly extracted from herbs, tree bark, plants and food. For example, in the 17th century, the Peruvian Indians ate cinchona bark when they had a fever. They learned this from experience only. Until 1816, some pharmacists extracted quinine from the cinchona bark. It is used in the treatment of malaria, a disease transmitted by the anopheles mosquito and common in the tropical countries. Quinine is also used to help cure other diseases. However, if a child use quinine for a long time, he or she will have rickets.

Years ago, ________.