YOU SAID:

My science teacher had a cow because i was web browsing

INTO JAPANESE

私はウェブブラウザだったので私の科学の先生は牛を飼っていた

BACK INTO ENGLISH

My science teacher kept a cow because I was a web browser

INTO JAPANESE

私はウェブブラウザだったので私の科学の先生は牛を飼っていました

BACK INTO ENGLISH

My science teacher kept a cow because I was a web browser