I have a question about question number 4,Thank you for your help!

. China's Ministry of Finance issued bonds denominated in euros at a negative interest rate (-0.152%) for the first time on Nov. 19, 2020 in a bond sale that attracted signicant investor interest. . What countries/regions have negative interest rates now? Why can such phenomenon happen? . Why would investors like to invest in bonds with negative yields? . What are the potential positive and negative effects of negative interest rates? . The yield of the 5-year treasury bonds in China is around 3% in November 2020. Why didn't the Chinese government issue more bonds to raise funds in areas with negative interest rates? Why would foreign investors like to buy China's treasury bonds with a negative yield rather than those with a positive yield in China's bond market