How did the United States intervene and help with the Chernobyl nuclear accident? Please put years and exact dates with hours if possible, because I need this answer to make a timeline.

All of the following were weaknesses of the articles of confederation, except: a) the central government was not permitted to regulate state, interstate, or foreign trade. b) the central government was not permitted to borrow money. c) the central government had little ability to regulate money. d) the central government had no ability to tax.