Answer:
Since the middle of the 20th century, scientists <u>have found</u> cures for many diseases. However, so far no one <u>has discovered</u>
Explanation:
those are the perfect tenses for (find) and (discover)
Answer:
put it into your own words trmnvfn sorry bout that my computers being stupid wont let backspace and gibberish was accient
also didnt mean to vote on it woopsie
Explanation: