perfection
尽善尽美，完整无缺   

例句：
She aims at perfection in everything she does.
她做任何事都希望尽善尽美。
 

head and shoulders
大大地，远胜于
 
例句：
This coffee is head and shoulders above the brand we had last week.
这种咖啡远比我们上星期喝的那种牌子的咖啡好。

It's a piece of cake.
这很容易。

对话：
A: Jack,can you play chess?
B: Of course, I can. It's a piece of cake. Even a child could do it.
A: But not me. Could you please teach me?
B: OK.
　　　
A：杰克，你会下棋吗？
B：当然会了。这非常简单，连小孩子都会的。
A：可是我不会。你能教教我吗？
B：好的。