The hot air moves up after it gets hot.滴意思,快

The hot air moves up after it gets hot.滴意思,快 the hot air moves up__it gets cold it cooled down the hot air HOT AIR的意思 The hot air makes the balloon stay up(划线提问) The hot air 划线 The hot air make the balloon stay up.中文是什么 because it gets very hot i什么 the flat hot-air balloon的意思 full of hot air的意思,具体 first hot air balloon啥意思? HOT!HOT!HOT!It's so hot! hot hot hot 的意思