a par for the course
[俚]预料中的事情

It was a par for the course that he failed in the final exam.
他期末考试不及格是预料中的事情。

注解：
par指常态，正常，course指路径，路程；a par for the course指顺理成章，在意料之中。

keep company with somebody
[俗]约会；成为确定关系的情侣

Frank is keeping company with Connie now, and they plan to get married next year.
富兰克常与康妮约会，他们计划在来年结婚。

注解：
keep意指保持，company意指伙伴；to keep company with somebody此词原指陪伴某人，引申为与某人约会，或成为关系确定的伴侣。

save one’s skin
[俚]使安然无恙；毫发无损

When the enemy came to the village, the child was hidden in a barrel, which saved his skin. And all the others were killed.
当敌人来到这个村子的时候，那个孩子被藏在一个桶里，使他安然无恙。其他所有人都被杀了。

注解：
save指挽救，留下来，skin指皮肤；to save one’s skin指保住了某人的安全，喻指使其安然无恙，毫发无损地脱离险境。