Six-pack:

六塊腹肌

例句： 

He has a six-pack stomach and is extremely well-proportioned. 

他六塊腹肌發(fā)達，體型勻稱優(yōu)美。

Firm abs:

馬甲線

例句： 

Her body is so well proportioned, especially her firm abs. 

她的身材勻稱極了，尤其是她那結(jié)實的馬甲線。

V line abs:

人魚線

例句： 

His V line abs are easy on the eyes.

他的人魚線很養(yǎng)眼。