“____” – “For” answers the question...

Câu hỏi: “____” – “For” answers the question "How long” and “Since” answers the question “When".

A. What are the meanings of “for” and “since”?

B. What's the difference between “for” and “since”?

C. How to see the difference between “for” and “since”?

D. How similar are “for” and “since”?