the [ ]children are singing english songs.the children are singing english songs[ ].the children
问题描述：
the [ ]children are singing english songs.the children are singing english songs[ ].the children
are singinf english songs because of their[ ].《happy》
答
the [ happy]children are singing english songs.the children are singing english songs[happily ].the children are singing english songs because of their[ happiness].最后一个我不明白孩子在英文歌因为他们很幸福。happiness做名词讲，表示“幸福”的意思.1.development 名词形式2.developed 发达国家3.develops 第三人称单数4.developing发展中国家