非常开心的英文：
as a dog with two tails

参考例句：

She is so happy to break ties with him.
与他断绝关系使她非常开心。

The party was really neat——we had good fun.
这次聚会真是美妙极了——我们玩得非常开心。

Those Mohammedan would feel so happy on that day.
那些伊斯兰教徒在那一天会感到非常开心。

even the monkeys hurried from their path with contortions and grimaces which convulsed Passepartout with laughter
在这一天当中，沿途很少看到野兽，偶尔有几只猢狲一边溜着，一边挤眉弄眼作出各种怪相。这使路路通非常开心。

dog是什么意思：
n. 狗；家伙
v. 跟踪，追踪

Is this dog trained?
这狗受过排便训练吗？

As faithful as a dog.
像狗一般的忠诚。

In the dog　house
窘迫,陷入困境

two是什么意思：
num. 二，两个
n. 两个人
adj. 两个的

Knit two, purl two.
两针朝下，两针朝上。

the better of the two
两者中的更好者

What does two and two make?
2加2等于几？

tails是什么意思：
n. 尾巴；尾部；辫子；燕尾服；尾随者
v. 跟踪，尾随

the tail of a train
火车的尾部

A human being has the vestige of a tail.
人类仍有尾巴退化的痕迹。

The police have got a tail on the criminal.
警察雇到一名暗探跟踪罪犯。