how happy they are playing!

how happy they are playing! how happy they are playing 改错, How () happy they are! they are playing with snow ()(happy) They are playing ------{happy} under the tree. They are playing together ----------(happy/happily) They are playing games_____(happy).They are very___________( they are -------(happy)boys aer playing -------(happy） How happy they are. 什么意思? How _____ (happy) they are relaxing! Look ! How ? (happy) the children are playing in the park . How can they be happy i____ they are not free?