根据对话意思和所给首字母，写出完整正确的单词。
Betty：Well, it's great to be here in Beijing．
Helen：Yes, it's exciting．Lots of 1．c________ take place every day．
Betty：And the Olympics are coming．I think Beijing is really the place to be right now．
Helen：Yes, 2．m________people are curious about Beijing than before．They all want to see it themselves．
Betty：Beijing is really a great city．But there are also some problems, such as pollution and 3．c________ traffic．
Helen：You're right．There are a lot of challenges(挑战,)．
Betty：So our government has started“The Green Olympics Action Plan”to 4．b________Beijing into a better place to live in．
Helen：That sounds great．We all 5．h________the Olympics will be a great success．
