Rearrange the following five sentences (A), (B), (C), (D) and (E) in the proper sequence to form a meaningful paragraph; then answer the questions given below them.
A.Last March, I was invited to present a paper on the topic of whether the mistakes of the 20th century would be repeated in the 21st century as well.
B.The economic crisis hadn't become grave then.
C.But today the world is in the midst of the biggest economic crisis since 1929.
D.The key difference between then and now is that the old power structures have finally disappeared.
E.Now even the US is pleading for financial help from China.