无忧无虑carefree and without worries

喜气洋洋jubilant

喜闻乐见a delight to see;an attractive spectacle

下不为例never again;just this once;not to be repeated

显而易见clearly and easy to see;obviously

先见之明foresight

想方设法to think up every possible method;to devise ways and means;to try this;that and the other

相辅相成to complement one another

小心翼翼cautious and solemn;very carefully;prudent;gently and cautiously

心不在焉absent-minded