Vocabulaire anglais : Scientific progress

Complete the following sentences about scientific progress using these words: 'innovation', 'breakthrough', 'research', 'experiment'. 1. The university team spent ten years of $research$ to understand the impact of $CO_2$ on the climate. 2. Developing an efficient way to store solar energy was a major technological $innovation$ that changed the industry. 3. The laboratory team had to conduct a controlled $experiment$ to verify if the new material could withstand temperatures above $500 ^\circ C$. 4. The discovery of penicillin was a medical $breakthrough$ that saved millions of lives.