13. You had better keep your cell phone off when you go to bed.
你睡覺時最好把手機關了。
還能這樣說：
I suggest turning your phone off when you sleep.
You should make your phone off while you have a sleep.
諺語：
Don't keep all your eggs in one basket.
勿孤注一擲。
14. I forgot to pay my phone yesterday.
我昨天忘了給手機交話費了。
還能這樣說：
I omitted paying my phone bill yesterday.
I neglected to pay my phone yesterday.
諺語：
Elephants never forget.
象不忘事。
15. Your phone bill is due.
該交話費了。
還能這樣說：
You have got a phone due to make.
You should hand over your phone fee.
應用解析：
due from 應收；
due to 由于、起因于，歸功于；
become due 到期，滿期
16. My cell phone is broken.
我的手機壞了。
還能這樣說：
My cell phone doesn't work.
My mobile phone is out of order.
應用解析：
have a break 休息一會兒；
break from the past 和過去決裂；
break down 失敗毀掉，拆除