translation.en: It's very difficult to develop new drugs, and the reason it's difficult to develop new drugs is because in the early stages of drug development, the drugs are very risky, and they're very expensive.
translation.zh: 导致研究新药非常困难 而困难的原因在于 新药研究的早期阶段 研究药品投资风险大, 而且十分昂贵