bacteria are an annoying problem for astronauts.
细菌对宇航员来说是个恼人的问题。
2019全国卷2
For the past two years, Gordon's students have been studying ways to killbacteria in zero gravity, and they think they're close to a solution(解决方案).
在过去的两年里, 戈登的学生们一直在研究在零重力下杀死细菌的方法, 他们认为他们已经接近一个解决方案。
2019全国卷2