科学家们正在努力研发针对这种疾病的疫苗。

___Scientists are working to create a vaccine for the disease.

美国国家航空航天局近日宣布，将派遣一支训练有素的科学家团队前往火星。

NASA recently announced that they will send a team of highly trained ___scientists to Mars.

居里夫人是一位著名的科学家，她在放射性研究方面做了开创性的工作。

Marie Curie was a famous ___scientist who conducted pioneering research on radioactivity.