YOU SAID:

Scientists have been trying to do this for a long time

INTO JAPANESE

科学者たちは長い間これを試みてきた

BACK INTO ENGLISH

Scientists have been trying to do this for a long time.

INTO JAPANESE

科学者たちは長い間これをやろうとしてきました。

BACK INTO ENGLISH

Scientists have been trying to do this for a long time.