Your days are numbered if you keep driving while drunk.
(your days are numbered means you will die soon)
（your days are numbered指很快就会死去）
OK, I'll come to the party Friday. But Saturday it'll be time to hit the books.
(hit the books means study)
（hit the books指用功学习）
I have to get up at 5:00 tomorrow morning. It's time to hit the hay.
(hit the hay means go to bed)
（hit the hay 指上床睡觉）
I'll be out of town this weekend, but I'll be in touch when I get back Sunday night.
(in touch means in contact)
Social media are great for finding old friends with whom you've lost touch.
(lose touch means fall out of contact)