发布时间：2016-03-18 来源：环球网校 发布人：wyznl
Pain is the most common reason we go to a doctor. It is the most common reason we take medicines. Until recently, however, most doctors knew of only a few drugs that stopped some pains. ________. But new knowledge about the process of pain is helping them to control pain better.
A、Yet we need pain.
B、They knew little about the process of pain itself.
C、And others have painful attacks all the time.
D、It is our body's Warning system.